OPTIMAL CONTROL OF THERMALLY CONVECTED FLUID FLOWS \\Lambda K. ITO y AND S.S. RAVINDRAN y
OPTIMAL CONTROL OF THERMALLY CONVECTED FLUID FLOWS \\Lambda K. ITO y AND S.S. RAVINDRAN y Abstract. We examine the optimal control of stationary thermally convected fluid flows from the the oretical and numerical point of view. We use thermal convection as control mechanism, that is, control is effected
Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow
Donna Post Guillen
2009-07-01
A hydrodynamic model of two-phase, churn-turbulent flows is being developed using the computational multiphase fluid dynamics (CMFD) code, NPHASE-CMFD. The numerical solutions obtained by this model are compared with experimental data obtained at the TOPFLOW facility of the Institute of Safety Research at the Forschungszentrum Dresden-Rossendorf. The TOPFLOW data is a high quality experimental database of upward, co-current air-water flows in a vertical pipe suitable for validation of computational fluid dynamics (CFD) codes. A five-field CMFD model was developed for the continuous liquid phase and four bubble size groups using mechanistic closure models for the ensemble-averaged Navier-Stokes equations. Mechanistic models for the drag and non-drag interfacial forces are implemented to include the governing physics to describe the hydrodynamic forces controlling the gas distribution. The closure models provide the functional form of the interfacial forces, with user defined coefficients to adjust the force magnitude. An optimization strategy was devised for these coefficients using commercial design optimization software. This paper demonstrates an approach to optimizing CMFD model parameters using a design optimization approach. Computed radial void fraction profiles predicted by the NPHASE-CMFD code are compared to experimental data for four bubble size groups.
Euler's fluid equations: Optimal Control vs Optimization
Darryl D. Holm
2009-09-28
An optimization method used in image-processing (metamorphosis) is found to imply Euler's equations for incompressible flow of an inviscid fluid, without requiring that the Lagrangian particle labels exactly follow the flow lines of the Eulerian velocity vector field. Thus, an optimal control problem and an optimization problem for incompressible ideal fluid flow both yield the \\emph {same} Euler fluid equations, although their Lagrangian parcel dynamics are \\emph{different}. This is a result of the \\emph{gauge freedom} in the definition of the fluid pressure for an incompressible flow, in combination with the symmetry of fluid dynamics under relabeling of their Lagrangian coordinates. Similar ideas are also illustrated for SO(N) rigid body motion.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-03-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-08-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Fluid Flow Modeling in Fractures
Sarkar, Sudipta
2004-01-01
In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...
Acoustic concentration of particles in fluid flow
Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)
2010-11-23
An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.
McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.
1993-11-30
A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.
McKay, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)
1993-01-01
A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.
Insertable fluid flow passage bridgepiece and method
Jones, Daniel O. (Glenville, NV)
2000-01-01
A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.
Fluid flow effects on electroplating
Kirkpatrick, J.R.
1990-09-01
The effects of fluid flow patterns on the electroplating of rotating cylindrically symmetric objects are examined. Ways are outlined for preventing undesirable spiral patterns on the plated surface. Estimates are given for the diffusion boundary later thickness for cylinders, disks, spheres, and cones. 16 refs., 7 figs., 1 tab.
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW
Santos, Juan
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. II CO2 is separated from natural
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW
Santos, Juan
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1 1 Department of Mathematics, Purdue University, USA Purdue University, March 1rst, 2013 SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12 (North Sea). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. II CO2 is separated
Fluid Flow Estimation Through Integration of Physical Flow Configurations
Garbe, Christoph S.
Fluid Flow Estimation Through Integration of Physical Flow Configurations Christoph S. Garbe IWR, University of Heidelberg Christoph.Garbe@iwr.uni-heidelberg.de Abstract. The measurement of fluid flows is an emerging field for op- tical flow computation. In a number of such applications, a tracer is visualized
Fluid properties determine flow line blockage potential
Hunt, A.
1996-07-15
A thorough understanding of fluid properties helps in determining the potential of hydrates, paraffins, or asphaltenes to block subsea flow lines. Thermal, chemical, and mechanical methods are the main ways for preventing deposition. Already in both the North Sea and the Gulf of Mexico, blockages have led to significant losses in production and reserves recovery. This first article in a two-part series discusses thermal and chemical methods in overcoming fluid behavior problems caused by hydrate and other fluid constituents in subsea multiphase flow. The paper discusses subsea production, possible problems, nucleation, growth, deposition, preventing deposition, hydrate predictions, multiphase flow, and hydrate inhibition.
Modeling fluid flow in deformation bands with stabilized localization...
Office of Scientific and Technical Information (OSTI)
Modeling fluid flow in deformation bands with stabilized localization mixed finite elements. Citation Details In-Document Search Title: Modeling fluid flow in deformation bands...
Application of Neutron Imaging and Scattering to Fluid Flow and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS...
Fracture Network and Fluid Flow Imaging for EGS Applications...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure Fracture Network and Fluid Flow Imaging for EGS Applications from...
Addendum to fluid flow effects on electroplating
Kirkpatrick, J.R.
1990-10-01
Expressions are given for concentration boundary layer thickness on complex axisymmetric shapes for use in electroplating calculations. This is an addendum to a discussion of fluid flow effects in electroplating. 6 refs., 1 fig.
Shear flow instabilities in viscoelastic fluids
Miller, Joel C.
2006-05-23
. . . . . . . . . . . 16 1.3.1 Flows with curved streamlines . . . . . . . . . . . . . . 16 1.3.2 Flows with straight streamlines . . . . . . . . . . . . . 17 1.4 Theoretical study of extrusion flow . . . . . . . . . . . . . . . 18 1.4.1 Single fluid... pipe, a phenomenon known as turbulent drag reduction. This has applications including fire hose design, waste water disposal, and crude oil transport. The phenomenon is not well understood, in part because even the simplest effects of polymers on high...
Directed flow fluid rinse trough
Kempka, Steven N. (9504 Lona La., Albuquerque, NM 87111); Walters, Robert N. (11872 LaGrange St., Boise, ID 83709)
1996-01-01
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs.
Directed flow fluid rinse trough
Kempka, S.N.; Walters, R.N.
1996-07-02
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs. 9 figs.
Method and apparatus for controlling fluid flow
Miller, J.R.
1980-06-27
A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.
Microfluidics: Kinetics of Hybridized DNA With Fluid Flow Variations...
Office of Scientific and Technical Information (OSTI)
Conference: Microfluidics: Kinetics of Hybridized DNA With Fluid Flow Variations. Citation Details In-Document Search Title: Microfluidics: Kinetics of Hybridized DNA With Fluid...
Synovial fluid homeostasis : bulk flow, lubricant transport, and biophysical restoration
McCarty, William Joseph
2012-01-01
of synovial fluid lubricants hyaluronan and proteoglycan 4HOMEOSTASIS: BULK FLOW, LUBRICANT TRANSPORT, AND BIOPHYSICALmodel of synovial fluid lubricant composition in normal and
Optimal Demand Response and Power Flow
Willett, Rebecca
Optimal Demand Response and Power Flow Steven Low Computing + Math Sciences Electrical Engineering #12;Outline Optimal demand response n With L. Chen, L. Jiang, N. Li Optimal power flow n With S. Bose;Optimal demand response Model Results n Uncorrelated demand: distributed alg n Correlated demand
Ultrasonic fluid flow measurement method and apparatus
Kronberg, J.W.
1993-10-12
An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible. 3 figures.
Ultrasonic fluid flow measurement method and apparatus
Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)
1993-01-01
An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.
Problems of fluid flow in a deformable reservoir
Diyashev, Ildar
2006-04-12
This research is focused on development and enhancement of the model of fluid flow in a formation with stress-dependent permeability. Several typical axi-symmetrical problems of fluid flow in a multi-layered reservoir with ...
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Can We Accurately Model Fluid Flow in Shale? Can We Accurately Model Fluid Flow in Shale? Print Thursday, 03 January 2013 00:00 Over 20 trillion cubic meters of natural gas are...
Flame Enhancement and Quenching in Fluid Flows Natalia Vladimirova
Kiselev, Alex
Flame Enhancement and Quenching in Fluid Flows Natalia Vladimirova , Peter Constantin , Alexander scale of the flow and laminar front thickness. For cellular flow, we obtain v U1/4 . We also study speed of the flame can be significantly altered by the fluid flow. Specifically, moderately intense
Active polar fluid flow in finite droplets
Carl A. Whitfield; Davide Marenduzzo; Raphaël Voituriez; Rhoda J. Hawkins
2014-02-19
We present a continuum level analytical model of a droplet of active contractile fluid consisting of filaments and motors. We calculate the steady state flows that result from a splayed polarisation of the filaments. We account for the interaction with an arbitrary external medium by imposing a viscous friction at the fixed droplet boundary. We then show that the droplet has non-zero force dipole and quadrupole moments, the latter of which is essential for self-propelled motion of the droplet at low Reynolds' number. Therefore, this calculation describes a simple mechanism for the motility of a droplet of active contractile fluid embedded in a 3D environment, which is relevant to cell migration in confinement (for example, embedded within a gel or tissue). Our analytical results predict how the system depends on various parameters such as the effective friction coefficient, the phenomenological activity parameter and the splay of the imposed polarisation.
Chang, F.C.; Hull, J.R.; Wang, Y.H.; Blazek, K.E.
1996-02-01
A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D) finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA is able to predict the eddy- current distribution and the electromagnetic forces in complex geometries. CaPS-EM is capable of modeling fluid flows with free surfaces. Results of the numerical simulation compared well with measurements obtained from a static test.
NMRI methods for characterizing fluid flow in porous media
Yao, Xiaoli
1997-01-01
Many important processes such as petroleum production and catalytic chemical reactions involve the flow of fluids through porous media. The measurement of localized velocity can provide information about how fluid is transported in porous media...
Curl-Noise for Procedural Fluid Flow Robert Bridson
Bridson, Robert
Curl-Noise for Procedural Fluid Flow Robert Bridson University of British Columbia Jim Hourihan), exactly respects solid boundaries (not allowing fluid to flow through arbitrarily-specified surfaces, without manually adding many vortices, this approach is restricted to fairly laminar flow, and matching
Enhancing cancer therapeutics using size-optimized magnetic fluid hyperthermia
Krishnan, Kannan M.
Enhancing cancer therapeutics using size-optimized magnetic fluid hyperthermia Amit P. Khandhar, R cancer therapeutics using size-optimized magnetic fluid hyperthermia Amit P. Khandhar,1 R. Matthew & Engineering, Seattle, Washington 98195, USA 2 Fred Hutchinson Cancer Research Center, Division of Clinical
Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...
Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of Tracer-Determined Residence Time Distributions Jump to: navigation, search OpenEI Reference LibraryAdd to library...
Fluid flow plate for decreased density of fuel cell assembly
Vitale, N.G.
1999-11-09
A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.
Fluid flow plate for decreased density of fuel cell assembly
Vitale, Nicholas G.
1999-01-01
A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.
Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium...
Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Trends Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Flow Of Mantle...
Nonlinear dynamics of three dimensional fluid flow separation
Surana, Amit
2007-01-01
Flow separation (the detachment of fluid from a no-slip boundary) is a major cause of performance loss in engineering devices, including diffusers, airfoils and jet engines. The systematic study of flow separation dates ...
Optimized boundary driven flows for dynamos in a sphere
Khalzov, I. V.; Brown, B. P.; Cooper, C. M.; Weisberg, D. B.; Forest, C. B. [Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
2012-11-15
We perform numerical optimization of the axisymmetric flows in a sphere to minimize the critical magnetic Reynolds number Rm{sub cr} required for dynamo onset. The optimization is done for the class of laminar incompressible flows of von Karman type satisfying the steady-state Navier-Stokes equation. Such flows are determined by equatorially antisymmetric profiles of driving azimuthal (toroidal) velocity specified at the spherical boundary. The model is relevant to the Madison plasma dynamo experiment, whose spherical boundary is capable of differential driving of plasma in the azimuthal direction. We show that the dynamo onset in this system depends strongly on details of the driving velocity profile and the fluid Reynolds number Re. It is found that the overall lowest Rm{sub cr} Almost-Equal-To 200 is achieved at Re Almost-Equal-To 240 for the flow, which is hydrodynamically marginally stable. We also show that the optimized flows can sustain dynamos only in the range Rm{sub cr}
Optimal Power Flow Based Demand Response Offer Price Optimization
Lavaei, Javad
Optimal Power Flow Based Demand Response Offer Price Optimization Zhen Qiu 1 Introduction-time energy balance. Demand response programs are offered by the utility companies to reduce the load response cost in exchange for load reduction. A considerable amount of papers have discussed the demand
Method and apparatus for chemically altering fluids in continuous flow
Heath, William O. (Richland, WA); Virden, Jr., Judson W. (Richland, WA); Richardson, R. L. (West Richland, WA); Bergsman, Theresa M. (Richland, WA)
1993-01-01
The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation.
Method and apparatus for chemically altering fluids in continuous flow
Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.
1993-10-19
The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation. 4 figures.
Application of optimal homotopy asymptotic method to nonlinear Bingham fluid dampers
Marinca, Vasile; Bereteu, Liviu
2015-01-01
Magnetorheological fluids (MR) are stable suspensions of magnetizable microparticles, characterized by the property to change the rheological characteristics when subjected to the action of magnetic field. Together with another class of materials that change their rheological characteristics in the presence of an electric field, called electrorheological materials are known in the literature as the smart materials or controlled materials. In the absence of a magnetic field the particles in MR fluid are dispersed in the base fluid and its flow through the apertures is behaves as a Newtonian fluid having a constant shear stress. When the magnetic field is applying a MR fluid behavior change, and behaves like a Bingham fluid with a variable shear stress. Dynamic response time is an important characteristic for determining the performance of MR dampers in practical civil engineering applications. The purpose of this paper is to show how to use the Optimal Homotopy Asymptotic Method (OHAM) to solve the nonlinear d...
Friction-Induced Fluid Heating in Nanoscale Helium Flows
Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)
2010-05-21
We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.
Optimal Average Cost Manufacturing Flow Controllers
Veatch, Michael H.
policy the differ- ential cost is C1 on attractive control switching boundaries. Index Terms Average costOptimal Average Cost Manufacturing Flow Controllers: Convexity and Differentiability Michael H and differentiability of the differential cost function are investigated. It is proven that under an optimal control
Network Flow Optimization under Uncertainty
Tesfatsion, Leigh
, production, generation, transportation, trade, storage injections and withdrawals of coal, gas?) xij is flow along arc (i, j), from node i to node j cij is cost per unit of flow along (i, j Network model in words Minimize the cost of satisfying demands for electric energy By: imports, exports
Acoustic geometry for general relativistic barotropic irrotational fluid flow
Visser, Matt
2010-01-01
"Acoustic spacetimes", in which techniques of differential geometry are used to investigate sound propagation in moving fluids, have attracted considerable attention over the last few decades. Most of the models currently considered in the literature are based on non-relativistic barotropic irrotational fluids, defined in a flat Newtonian background. The extension, first to special relativistic barotropic fluid flow, and then to general relativistic barotropic fluid flow in an arbitrary background, is less straightforward than it might at first appear. In this article we provide a pedagogical and simple derivation of the general relativistic "acoustic spacetime" in an arbitrary (d+1) dimensional curved-space background.
Bacteria, Biofilms and Fluid Dynamics: Elementary Flows and Unexpected Phenomena
Fisher, Frank
Bacteria, Biofilms and Fluid Dynamics: Elementary Flows and Unexpected Phenomena Wednesday February the migration of bacteria along surfaces when exposed to a shear flow. In particular, we identify an unusual response where flow produces a directed motion of twitching bacteria in the upstream direction. (ii) We
Flow networks: A characterization of geophysical fluid transport
Enrico Ser-Giacomi; Vincent Rossi; Cristobal Lopez; Emilio Hernandez-Garcia
2015-03-05
We represent transport between different regions of a fluid domain by flow networks, constructed from the discrete representation of the Perron-Frobenius or transfer operator associated to the fluid advection dynamics. The procedure is useful to analyze fluid dynamics in geophysical contexts, as illustrated by the construction of a flow network associated to the surface circulation in the Mediterranean sea. We use network-theory tools to analyze the flow network and gain insights into transport processes. In particular we quantitatively relate dispersion and mixing characteristics, classically quantified by Lyapunov exponents, to the degree of the network nodes. A family of network entropies is defined from the network adjacency matrix, and related to the statistics of stretching in the fluid, in particular to the Lyapunov exponent field. Finally we use a network community detection algorithm, Infomap, to partition the Mediterranean network into coherent regions, i.e. areas internally well mixed, but with little fluid interchange between them.
Feedback regulated induction heater for a flowing fluid
Migliori, Albert (Santa Fe, NM); Swift, Gregory W. (Los Alamos, NM)
1985-01-01
A regulated induction heater for heating a stream of flowing fluid to a predetermined desired temperature. The heater includes a radiofrequency induction coil which surrounds a glass tube through which the fluid flows. A heating element consisting of a bundle of approximately 200 stainless steel capillary tubes located within the glass tube couples the output of the induction coil to the fluid. The temperature of the fluid downstream from the heating element is sensed with a platinum resistance thermometer, the output of which is applied to an adjustable proportional and integral feedback control circuit which regulates the power applied to the induction coil. The heater regulates the fluid temperature to within 0.005.degree. C. at a flow rate of 50 cm.sup.3 /second with a response time of less than 0.1 second, and can accommodate changes in heat load up to 1500 watts.
Feedback regulated induction heater for a flowing fluid
Migliori, A.; Swift, G.W.
1984-06-13
A regulated induction heater for heating a stream of flowing fluid to a predetermined desired temperature. The heater includes a radiofrequency induction coil which surrounds a glass tube through which the fluid flows. A heating element consisting of a bundle of approximately 200 stainless steel capillary tubes located within the glass tube couples the output of the induction coil to the fluid. The temperature of the fluid downstream from the heating element is sensed with a platinum resistance thermometer, the output of which is applied to an adjustable porportional and integral feedback control circuit which regulates the power applied to the induction coil. The heater regulates the fluid temperature to within 0.005/sup 0/C at a flow rate of 50 cm/sup 3//sec with a response time of less than 0.1 second, and can accommodate changes in heat load up to 1500 watts.
Flow regimes for fluid injection into a confined porous medium
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zheng, Zhong; Guo, Bo; Christov, Ivan C.; Celia, Michael A.; Stone, Howard A.
2015-02-24
We report theoretical and numerical studies of the flow behaviour when a fluid is injected into a confined porous medium saturated with another fluid of different density and viscosity. For a two-dimensional configuration with point source injection, a nonlinear convection–diffusion equation is derived to describe the time evolution of the fluid–fluid interface. In the early time period, the fluid motion is mainly driven by the buoyancy force and the governing equation is reduced to a nonlinear diffusion equation with a well-known self-similar solution. In the late time period, the fluid flow is mainly driven by the injection, and the governingmore »equation is approximated by a nonlinear hyperbolic equation that determines the global spreading rate; a shock solution is obtained when the injected fluid is more viscous than the displaced fluid, whereas a rarefaction wave solution is found when the injected fluid is less viscous. In the late time period, we also obtain analytical solutions including the diffusive term associated with the buoyancy effects (for an injected fluid with a viscosity higher than or equal to that of the displaced fluid), which provide the structure of the moving front. Numerical simulations of the convection–diffusion equation are performed; the various analytical solutions are verified as appropriate asymptotic limits, and the transition processes between the individual limits are demonstrated.« less
Controls on Fault-Hosted Fluid Flow: Preliminary Results from...
Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Geothermal Field, CA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...
MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN
MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN A FINITE ELEMENT for the modeling of geomechanical effects induced by reservoir production/injection and the cyclic dependence
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
2013 00:00 Over 20 trillion cubic meters of natural gas are trapped in shale, but many shale oil and gas producers still use models of underground fluid flow that date back to...
The effect of fluid flow on coiled tubing reach
Bhalla, K.; Walton, I.C.
1996-12-31
A critical parameter to the success of many coiled tubing (CT) operations in highly deviated or horizontal wells is the depth penetration that can be attained before the CT buckles and locks up. Achieving a desired depth is always critical in CT operations and attaining an additional reach of a few hundred feet can be crucial. This paper addresses the effect of fluid flow in the CT and in the CT/wellbore annulus on the state of force and stress in the CT, and thereby predicts its effect on the reach attainable by the CT. The flow of fluid through the CT and annulus between the CT and borehole modifies the pressures and the effective force which governs the mechanical stability of the CT. The net force per unit length due to fluid flow in the coiled tubing and annulus between the coiled tubing casing/well is calculated in terms of the shear stress and its effect on the onset of buckling and lockup is determined. The model is then implemented in a full tubing forces calculation and the effect of flowing fluids and producing fluids on reach is analyzed. The new model is utilized in the design of commercial jobs. The exact analytic model shows that fluid flow inside the CT has zero impact on reach, that downward flow in the annulus has a favourable impact, and upward flow in the annulus reduces the maximum attainable reach. Using the full tubing forces model, a coiled tubing job can be designed taking into account the flow of a fluid with a specified rheology, density and flow rate. Thus the feasibility of attaining a given reach can be more accurately determined. Results are presented in the form of the surface weight for commercial wells and compared to field jobs.
System and method measuring fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID); Kidd, Terrel G. (Blackfoot, ID)
1999-01-01
A system for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements.
Following the flow: tracer particles in astrophysical fluid simulations
Genel, Shy; Nelson, Dylan; Sijacki, Debora; Springel, Volker; Hernquist, Lars
2013-01-01
We present two independent numerical schemes for passive tracer particles in the hydrodynamical moving-mesh code Arepo, and compare their performance for various problems, from simple tests to cosmological simulations. The purpose of tracer particles is to allow the flow to be followed in a Lagrangian way, reliably tracing the evolution of the fluid. Such tracer particles can subsequently measure any local instantaneous fluid property, thereby recording the thermodynamical history of individual fluid parcels. We begin by discussing "velocity field tracers", which are advected according to the local velocity field of the fluid, and which have been commonly used in the literature. We find that such tracers do not in general follow the mass flow correctly, particularly in complex flows, and explain why this is the case. This weakness of the method can result in orders-of-magnitude biases in simulations of driven turbulence and in cosmological simulations of structure formation, rendering the velocity field trace...
Revised: Thursday, February 25, 1999 Dynamics of osmotic fluid flow
Oster, George
Revised: Thursday, February 25, 1999 Dynamics of osmotic fluid flow George Oster Departments The classical thermodynamic treatment of osmotic pressure is quite sufficient to describe equilibrium situations can be quite useful when thinking about osmotic flow in unfamiliar situations. The equilibrium
A preliminary study to Assess Model Uncertainties in Fluid Flows
Marc Oliver Delchini; Jean C. Ragusa
2009-09-01
The goal of this study is to assess the impact of various flow models for a simplified primary coolant loop of a light water nuclear reactor. The various fluid flow models are based on the Euler equations with an additional friction term, gravity term, momentum source, and energy source. The geometric model is purposefully chosen simple and consists of a one-dimensional (1D) loop system in order to focus the study on the validity of various fluid flow approximations. The 1D loop system is represented by a rectangle; the fluid is heated up along one of the vertical legs and cooled down along the opposite leg. A pressurizer and a pump are included in the horizontal legs. The amount of energy transferred and removed from the system is equal in absolute value along the two vertical legs. The various fluid flow approximations are compressible vs. incompressible, and complete momentum equation vs. Darcy’s approximation. The ultimate goal is to compute the fluid flow models’ uncertainties and, if possible, to generate validity ranges for these models when applied to reactor analysis. We also limit this study to single phase flows with low-Mach numbers. As a result, sound waves carry a very small amount of energy in this particular case. A standard finite volume method is used for the spatial discretization of the system.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-08
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
Rutqvist, J.
2014-01-01
porosity models for fluid transport in jointed rock. Journalof coupled fluid flow, solute transport, and geomechanics ingeomechanics, fluid flow and transport in fractured rock
Optimal operation of a mixed fluid cascade LNG process
Skogestad, Sigurd
Optimal operation of a mixed fluid cascade LNG process Jørgen Bauck Jensen & Sigurd Skogestad distances is to first produce liquefied natural gas (LNG) and then transport the LNG by ships. At atmospheric pressure LNG has approximately 600 times the density of gaseous NG and a temperature of ap
Method, apparatus and system for controlling fluid flow
McMurtrey, Ryan D. (Idaho Falls, ID); Ginosar, Daniel M. (Idaho Falls, ID); Burch, Joesph V. (Shelley, ID)
2007-10-30
A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.
Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings
San Andres, Luis
2009-01-01
The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....
Computerized tomographic analysis of fluid flow in fractured tuff
Felice, C.W.; Sharer, J.C.; Springer, E.P.
1992-05-01
The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.
Computerized tomographic analysis of fluid flow in fractured tuff
Felice, C.W.; Sharer, J.C. ); Springer, E.P. )
1992-01-01
The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.
Electromagnetic Radiations as a Fluid Flow
Daniele Funaro
2009-11-25
We combine Maxwell's equations with Eulers's equation, related to a velocity field of an immaterial fluid, where the density of mass is replaced by a charge density. We come out with a differential system able to describe a relevant quantity of electromagnetic phenomena, ranging from classical dipole waves to solitary wave-packets with compact support. The clue is the construction of an energy tensor summing up both the electromagnetic stress and a suitable mass tensor. With this right-hand side, explicit solutions of the full Einstein's equation are computed for a wide class of wave phenomena. Since our electromagnetic waves may behave and interact exactly as a material fluid, they can create vortex structures. We then explicitly analyze some vortex ring configurations and examine the possibility to build a model for the electron.
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW
First industrial scale CO2 injection project: Sleipner gas field (North Sea). ... The Black-Oil formulation of two-phase flow in porous media ... Attenuation adn dispersion in the periodic gas-water case is in perfect agreement with that predicted by ...
Paris-Sud XI, Université de
SUBMITTED TO THE INTERNATIONAL JOURNAL OF FLOW CONTROL, REVISED VERSION 1 Fluid Flow Control, by visualizing a fluid flow, dense flow velocity maps can be computed via optical flow techniques by diminishing the fuel consumption of their aircrafts through drag reduction [1]. In contrast, in other
Design considerations for inverters in fluid flow control
Guggari, Mallappa Ishwarappa
1989-01-01
. 18 power circuit of current source inverter 3. 19 Output waveforms of current source inverter 5. 1 Response of fluid flow control system to a ramp reference input . 5. 2 Load torque and acceleration torque characteristics with centrifugal pump.... The process industry specifications for flow control have also become stringent, demanding an alternative to throttle valve control system, which is plagued with problems like poor dynamic response, dead- band, etc. In the literature, most of the attention...
Optimizing interventions for the treatment of vascular flow disruptions
Boval, Brett Lawrence
2014-01-01
All tissues rely on perfusion and therefore intact blood flow. When flow is disrupted the coupled interaction between the functional and fluid domains of a tissue is impeded and viability is lost. Aortic stenosis is a ...
Carrillo, Jose-Antonio Goudon, Thierry Lafitte, Pauline
2008-08-10
In this work, we propose asymptotic preserving numerical schemes for the bubbling and flowing regimes of particles immersed in a fluid treated by two-phase flow models. The description comprises compressible Euler equations for the dense phase (fluid) and a kinetic Fokker-Planck equation for the disperse phase (particles) coupled through friction terms. We show numerical simulations in the relevant case of gravity in the one-dimensional case demonstrating the overall behavior of the schemes.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, M.G.; Boucher, T.J.
1997-06-24
A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, Marcos G. (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
1997-01-01
A system for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N. (Los Alamos, NM)
2007-06-12
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive Characterization Of A Flowing Multiphase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
2005-05-10
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N.
2003-11-11
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Optimal power flow in microgrids using event-triggered optimization Pu Wan and Michael D. Lemmon
Lemmon, Michael
Optimal power flow in microgrids using event-triggered optimization Pu Wan and Michael D. Lemmon Abstract-- Microgrids are power generation and distribution systems in which users and generators-triggered distributed optimization algorithm to solve the optimal power flow (OPF) problem in microgrids. Under event
Su, Susan Shan
2007-01-01
suggesting that laminar fluid flow may deactivate the cellbe responsive to a laminar fluid flow field, few have beencell response to laminar fluid flow the roundness ratio (see
A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...
multicomponent fluid and heat flow through porous and fractured rock. Fracture and matrix flow is treated using both dual-permeability and effective-continuum modeling...
Optimized Natural-Laminar-Flow Airfoils and D. W. Zingg
Zingg, David W.
Optimized Natural-Laminar-Flow Airfoils J. Driver and D. W. Zingg University of Toronto Institute-Krylov aerodynamic shape optimization algorithm has been modified to incorporate the prediction of laminar natural-laminar-flow airfoils. In particular, the optimization algorithm is able to design an airfoil
Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control
Cary, Robert B.
2015-12-08
Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.
Controlling chaos in a fluid flow past a movable cylinder Juan C. Vallejo a
Rey Juan Carlos, Universidad
mechanisms are not yet well known. This paper analyzes the fluid flow past a cylinder in a laminar regime of an in- compressible, viscid, time-dependent fluid flow past a cylinder in the laminar vortex sheddingControlling chaos in a fluid flow past a movable cylinder Juan C. Vallejo a , Inees P. Mari
Convective flow of sisko fluid over a bidirectional stretching sheet
Munir, Asif; Khan, Masood
2014-01-01
The present investigation discusses the flow and heat transfer characteristics of a steady three dimensional Sisko fluid. The flow is induced due to bidirectional stretching sheet. The influence of power-law index and stretching ratio on flow and heat transfer is studied thoroughly. Governing partial differential equations are reduced to coupled ordinary differential equations by suitable similarity variable. The resulting equations are then solved numerically by shooting method using adaptive Runge Kutta algorithm in combination with Broyden's method in the domain . The numerical results for the velocity and temperature fields are graphically presented and effects of the relevant parameters are discussed in detail. Moreover, the skin-friction coefficient and local Nusselt number for different values of the power-law index and stretching ratio are presented through tabulated data. The numerical results are verified with the results obtained by HAM. Additionally, the results are also validated with previously ...
Distributed Algorithms for Optimal Power Flow Problem
Lam, Albert Y S; Tse, David
2011-01-01
Optimal power flow (OPF) is an important problem for power generation and it is in general non-convex. With the employment of renewable energy, it will be desirable if OPF can be solved very efficiently so its solution can be used in real time. With some special network structure, e.g. trees, the problem has been shown to have a zero duality gap and the convex dual problem yields the optimal solution. In this paper, we propose a primal and a dual algorithm to coordinate the smaller subproblems decomposed from the convexified OPF. We can arrange the subproblems to be solved sequentially and cumulatively in a central node or solved in parallel in distributed nodes. We test the algorithms on IEEE radial distribution test feeders, some random tree-structured networks, and the IEEE transmission system benchmarks. Simulation results show that the computation time can be improved dramatically with our algorithms over the centralized approach of solving the problem without decomposition, especially in tree-structured...
Reducing or stopping the uncontrolled flow of fluid such as oil from a well
Hermes, Robert E
2014-02-18
The uncontrolled flow of fluid from an oil or gas well may be reduced or stopped by injecting a composition including 2-cyanoacrylate ester monomer into the fluid stream. Injection of the monomer results in a rapid, perhaps instantaneous, polymerization of the monomer within the flow stream of the fluid. This polymerization results in formation of a solid plug that reduces or stops the flow of additional fluid from the well.
The flow and heat transfer in a viscous fluid over an unsteady stretching surface
Ene, Remus-Daniel; Marinca, Bogdan
2015-01-01
In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.
Erosion of a granular bed driven by laminar fluid flow
A. E. Lobkovsky; A. V. Orpe; R. Molloy; A. Kudrolli; D. H. Rothman
2008-05-01
Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $\\theta$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $\\theta >\\theta_c$. We find that the Shields criterion describes the observed relationship $h_r \\propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $\\theta$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $\\theta - \\theta_c$ with exponent $1.75 \\pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.
A STUDY OF COMPUTATIONAL FLUID DYNAMICS APPLIED TO ROOM AIR FLOW
for supplying me a copy of his three-dimensional, laminar, constant density fluid flow computer program, whichi A STUDY OF COMPUTATIONAL FLUID DYNAMICS APPLIED TO ROOM AIR FLOW By JAMES W. WEATHERS Bachelor of the requirements for the Degree of MASTER OF SCIENCE May, 1992 #12;ii A STUDY OF COMPUTATIONAL FLUID DYNAMICS
Fluid mechanics experiments in oscillatory flow. Volume 1
Seume, J.; Friedman, G.; Simon, T.W.
1992-03-01
Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re{sub max}, Re{sub W}, and A{sub R}, embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA`s Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation).
2. Some simple models of fluid flow: exact solutions of the N-S equation
Read, Peter L.
2. Some simple models of fluid flow: exact solutions of the N-S equation To construct mathematical. Boundary conditions: fluid comes to rest at the walls z = ±h (`no-slip' condition, since flow is viscous flow remains rectilinear (`laminar'). If Re Recrit, turbulence usually sets in: We say
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
1982-05-04
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion. 3 figs.
Optimal flapping strokes for self-propulsion in a perfect fluid Shane D. Ross
Ross, Shane
Optimal flapping strokes for self-propulsion in a perfect fluid Shane D. Ross Abstract-- Some animals rely on flapping a symmetrical pair of jointed appendages to generate locomotion in a fluid. We in a perfect fluid. Furthermore, we determine which strokes yield the greatest locomotive efficiency, defined
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
1980-05-02
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.
Rotation free flow of noncompressible fluid through the rotating wheel of centrifugal pump
Tanski, Igor A
2008-01-01
The exact analytic solution is built for the plane flow of incompressible fluid through the wheel with profiles of blades approximating logarithmic spirals.
Spatial and temporal resolution of fluid flows: LDRD final report
Tieszen, S.R.; O`Hern, T.J.; Schefer, R.W.; Perea, L.D.
1998-02-01
This report describes a Laboratory Directed Research and Development (LDRD) activity to develop a diagnostic technique for simultaneous temporal and spatial resolution of fluid flows. The goal is to obtain two orders of magnitude resolution in two spatial dimensions and time simultaneously. The approach used in this study is to scale up Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) to acquire meter-size images at up to 200 frames/sec. Experiments were conducted in buoyant, fully turbulent, non-reacting and reacting plumes with a base diameter of one meter. The PIV results were successful in the ambient gas for all flows, and in the plume for non-reacting helium and reacting methane, but not reacting hydrogen. No PIV was obtained in the hot combustion product region as the seed particles chosen vaporized. Weak signals prevented PLIF in the helium. However, in reacting methane flows, PLIF images speculated to be from Poly-Aromatic-Hydrocarbons were obtained which mark the flame sheets. The results were unexpected and very insightful. A natural fluorescence from the seed particle vapor was also noted in the hydrogen tests.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, M.G.
1999-03-23
A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID)
1999-01-01
A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1
Peszynska, Malgorzata
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1 reservoir properties. Pore pressures from flow are used as loads for the geomechanics code
Theoretical and Numerical Simulation of Non-Newtonian Fluid Flow in Propped Fractures
Ouyang, Liangchen
2013-12-10
The flow of non-Newtonian fluids in porous media is important in many applications, such as polymer processing, heavy oil flow, and gel cleanup in propped fractures. Residual polymer gel in propped fractures results in low fracture conductivity...
Biosensor Arrays for Estimating Molecular Concentration in Fluid Flows
Abolfath-Beygi, Maryam
2011-01-01
This paper constructs dynamical models and estimation algorithms for the concentration of target molecules in a fluid flow using an array of novel biosensors. Each biosensor is constructed out of protein molecules embedded in a synthetic cell membrane. The concentration evolves according to an advection-diffusion partial differential equation which is coupled with chemical reaction equations on the biosensor surface. By using averaging theory methods and the divergence theorem, an approximate model is constructed that describes the asymptotic behaviour of the concentration as a system of ordinary differential equations. The estimate of target molecules is then obtained by solving a nonlinear least squares problem. It is shown that the estimator is strongly consistent and asymptotically normal. An explicit expression is obtained for the asymptotic variance of the estimation error. As an example, the results are illustrated for a novel biosensor built out of protein molecules.
Optimal Manufacturing Flow Controllers: Zero-Inventory Policies
Veatch, Michael H.
Optimal Manufacturing Flow Controllers: Zero-Inventory Policies and Control Switching Sets Michael, (978) 927-2300, FAX (978) 524-3747, veatch@gordonc.edu Department of Manufacturing Engineering, Boston Kimemia and Gershwin [12] proposed a flow control model of a flexible manufacturing system that has been
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2
Not Available
1992-06-01
The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s
Bahrami, Majid
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s A surface area, m Q 2 'T Ans. L V VV U PU § ·' : 3 3 3 3 ¨ ¸ © ¹ 5.18 Under laminar conditions, the volume flow Q through temperature difference, K The dimensionless form of h, called the Stanton number, is a combination of h, fluid
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation
Paris-Sud XI, Université de
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions-sur-Loing, France. Working on fluid mechanics aspects of nuclear valves since 2004. Zachary Leutwyler zleutwyler and numerical investigation of flow- induced forces and torque acting on linear and quarter turn valves. hal
Numerical modeling of fluid flow and time-lapse seismics to monitor CO2
Santos, Juan
Numerical modeling of fluid flow and time-lapse seismics to monitor CO2 Sequestration in aquifers J, ITALY). IMAL, 30/5/2014 Numerical modeling of fluid flow and time-lapse seismics to monitor CO2 Sequestration in aquifers Â p. #12;Introduction. I Storage of CO2 in geological formations is a procedure
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Boyer, Edmond
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1
Device and method for measuring fluid flow in a conduit having a gradual bend
Ortiz, M.G.; Boucher, T.J.
1998-11-10
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
Device and method for measuring fluid flow in a conduit having a gradual bend
Ortiz, Marcos German (Idaho Falls, ID); Boucher, Timothy J (Helena, MT)
1998-01-01
A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.
Optimizing drilling performance using a selected drilling fluid
Judzis, Arnis (Salt Lake City, UT); Black, Alan D. (Coral Springs, FL); Green, Sidney J. (Salt Lake City, UT); Robertson, Homer A. (West Jordan, UT); Bland, Ronald G. (Houston, TX); Curry, David Alexander (The Woodlands, TX); Ledgerwood, III, Leroy W. (Cypress, TX)
2011-04-19
To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Julia J. Mack; Khalid Youssef; Onika D. V. Noel; Michael Lake; Ashley Wu; M. Luisa Iruela-Arispe; Louis-S. Bouchard
2013-01-13
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Mack, Julia J; Noel, Onika D V; Lake, Michael; Wu, Ashley; Iruela-Arispe, M Luisa; Bouchard, Louis-S; 10.1016/j.biomaterials.2012.11.030
2013-01-01
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Synthetic aperture imaging for three dimensional resolution of fluid flows
Belden, Jesse (Jesse Levi)
2011-01-01
Fluid mechanics and instrumentation have a long history together, as experimental fluids studies play an important role in describing a more complete physical picture in a variety of problems. Presently. state-of-the-art ...
Kim, J.
2014-01-01
Settari A. Modeling of geomechanics in naturally fracturedway coupled fluid flow and geomechanics in hydrate deposits.for coupled flow and geomechanics: Drained and undrained
Kandlikar, Satish
, the effect of structured roughness elements on incompress- ible laminar fluid flow is analyzedA numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat flow Structured roughness elements Laminar flow a b s t r a c t Better understanding of laminar flow
Miniatuization of the flowing fluid electric conductivity loggingtec hnique
Su, Grace W.; Quinn, Nigel W.T.; Cook, Paul J.; Shipp, William
2005-10-19
An understanding of both the hydraulic properties of the aquifer and the depth distribution of salts is critical for evaluating the potential of groundwater for conjunctive water use and for maintaining suitable groundwater quality in agricultural regions where groundwater is used extensively for irrigation and drinking water. The electrical conductivity profiles recorded in a well using the flowing fluid electric conductivity logging (FEC logging) method can be analyzed to estimate interval specific hydraulic conductivity and estimates of the salinity concentration with depth. However, irrigation wells that are common in agricultural regions have limited access into them because these wells are still in operation, and the traditional equipment used for FEC logging cannot fit through the small access pipe intersecting the well. A modified, miniaturized FEC logging technique was developed such that this logging method could be used in wells with limited access. In addition, a new method for injecting water over the entire screened interval of the well was developed to reduce the time required to perform FEC logging. Results of FEC logging using the new methodology and miniaturized system in two irrigation wells are also summarized.
Optimal Frequency for Microfluidic Mixing across a Fluid Interface Sanjeeva Balasuriya*
Balasuriya, Sanjeeva
Optimal Frequency for Microfluidic Mixing across a Fluid Interface Sanjeeva Balasuriya* School microfluidic mixing examples based on electromagnetic forcing and fluid pumping strategies are presented. DOI appeared recently. A collection of review articles on microfluidic mixing devices appears in a dedi- cated
Rom-Kedar, Vered
flows Phys. Fluids 23, 016603 (2011); 10.1063/1.3531716 Development and characterization of a laminar of immiscible impurities in a two-dimensional flow Phys. Fluids 10, 342 (1998); 10.1063/1.869526 This articleNew Lagrangian diagnostics for characterizing fluid flow mixing Ruty Mundel, Erick Fredj, Hezi
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in
Maruyama, Shigeo
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level
Method and apparatus for measuring the mass flow rate of a fluid
Evans, Robert P. (Idaho Falls, ID); Wilkins, S. Curtis (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Blotter, Jonathan D. (Pocatello, ID)
2002-01-01
A non invasive method and apparatus is provided to measure the mass flow rate of a multi-phase fluid. An accelerometer is attached to a pipe carrying a multi-phase fluid. Flow related measurements in pipes are sensitive to random velocity fluctuations whose magnitude is proportional to the mean mass flow rate. An analysis of the signal produced by the accelerometer shows a relationship between the mass flow of a fluid and the noise component of the signal of an accelerometer. The noise signal, as defined by the standard deviation of the accelerometer signal allows the method and apparatus of the present invention to non-intrusively measure the mass flow rate of a multi-phase fluid.
Under consideration for publication in J. Fluid Mech. 1 Edges in Models of Shear Flow
Lebovitz, Norman
Under consideration for publication in J. Fluid Mech. 1 Edges in Models of Shear Flow Norman)). The latter problem is ap- proached theoretically by considering first a laminar shear flow (plane Couette of the laminar flow. This places particular importance on understanding the nature of the boundary of the basin
Laboratory studies of subaqueous debris flows by measurements of pore-fluid pressure and total flows is reported where total stress as well as pore pressure transducers were mounted in the bed; hydroplaning; laboratory experiment; pore pressure measurements 1. Introduction Debris flow is an important
Single-cycle mixed-fluid LNG process Part I: Optimal design
Skogestad, Sigurd
Single-cycle mixed-fluid LNG process Part I: Optimal design Jørgen Bauck Jensen and Sigurd the design optimization of a relatively simple LNG pro- cess; the PRICO process. A simple economic objective. Keywords: PRICO, LNG, design 1 Introduction Stebbing and O'Brien (1975) reported on the performance
Multiphase flow in the advanced fluid dynamics model
Bohl, W.R.; Wilhelm, D.; Berthier, J.; Parker, F.P.; Ichikawa, S.; Goutagny, L.; Ninokata, H.
1988-01-01
This paper describes the modeling used in the Advanced Fluid Dynamics Model (AFDM), a computer code to investigate new approaches to simulating severe accidents in fast reactors. The AFDM code has 12 topologies describing what material contacts are possible depending on the presence or absence of a given material in a computational cell, the dominant liquid, and the continuous phase. Single-phase, bubbly, churn-turbulent, cellular, and dispersed flow are permitted for the pool situations modeled. Interfacial areas between the continuous and discontinuous phases are convected to allow some tracking of phenomenological histories. Interfacial areas also are modified by models of nucleation, dynamic forces, turbulence, flashing, coalescence, and mass transfer. Heat transfer generally is treated using engineering correlations. Liquid/vapor phase transitions are handled with a nonequililbrium heat-transfer-limited model, whereas melting and freezing processes are based on equilibrium considerations. The Los Alamos SESAME equation of state (EOS) has been inplemented using densities and temperatures as the independent variables. A summary description of the AFDM numerical algorithm is provided. The AFDM code currently is being debugged and checked out. Two sample three-field calculations also are presented. The first is a three-phase bubble column mixing experiment performed at Argonne National Laboratory; the second is a liquid-liquid mixing experiment performed at Kernforschungszentrum, Karlsruhe, that resulted in rapid vapor production. We conclude that only qualitative comparisons currently are possible for complex multiphase situations. Many further model developments can be pursued, but there are limits because of the lack of a comprehensive theory, the lack of detailed multicomponent experimental data, and the difficulties in keeping the resulting model complexities tractable.
Department of Mathematics and Statistics Colloquium Modeling Geophysical Fluid Flows
Arnold, Elizabeth A.
, caves, sinkholes, fissures, etc. Because of this, water can flow through conduits or pipes in addition
Fluid Flow and Infiltration in Structured Fibrous Porous Media
Papathanasiou, Thanasis D.
2006-08-09
Present the results of an extensive computational investigation of flow through structured fibrous media.
DC Optimal Power Flow: Uniqueness and Chee Wei Tan
Tan, Chee Wei
the minimization of power transmission loss in DC-OPF and char- acterize the uniqueness of its solutions. This hasDC Optimal Power Flow: Uniqueness and Algorithms Chee Wei TanÝ , Desmond W. H. Cai£ and Xin LouÝ Ý and transmission loss in a power net- work subject to physical constraints governed by Kirchhoff's and Ohm's law [1
Thermal Unit Commitment Including Optimal AC Power Flow Constraints
Thermal Unit Commitment Including Optimal AC Power Flow Constraints Carlos Murillo{Sanchez Robert J algorithm for unit commitment that employs a Lagrange relaxation technique with a new augmentation. This framework allows the possibility of committing units that are required for the VArs that they can produce
Stress and Fluid-Flow Interaction for the Coso Geothermal Field...
Stress and Fluid-Flow Interaction for the Coso Geothermal Field Derived from 3D Numerical Models Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...
IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF...
IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings:...
Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs
Zapata Arango, Jose? Francisco
2002-01-01
more important. Modeling fluid flow in these systems must consider the dependence of relative permeability on both viscous and capillary forces. This research focuses on the evaluation of several recently proposed relative permeability models...
Lagrangian analysis of fluid transport in empirical vortex ring flows Shawn C. Shadden
Marsden, Jerrold
Lagrangian analysis of fluid transport in empirical vortex ring flows Shawn C. Shadden Control and Dynamical Systems, California Institute of Technology, Pasadena, California 91125 John O. Dabiri Graduate Aeronautical Laboratories and Bioengineering, California Institute of Technology, Pasadena, California 91125
Analysis of multiphase fluid flows via high speed and synthetic aperture three dimensional imaging
Scharfman, Barry Ethan
2012-01-01
Spray flows are a difficult problem within the realm of fluid mechanics because of the complicated interfacial physics involved. Complete models of sprays having even the simplest geometries continue to elude researchers ...
Numerical Simulation of the Flow of a Power Law Fluid in an Elbow Bend
Kanakamedala, Karthik
2010-07-14
equations are given by, ????? = ????? + ?? + ??? where, ? is the Laplacian operator ? is the density of the body ? is the body force ? is the velocity vector However, the fluid being dealt within the problem is a non-Newtonian power law fluid... parameters. This problem finds applications mainly in the food and polymer industries where non-Newtonian fluids flow through different piping sections. The elbow geometry used for performing the simulations consists of a straight portion of ??? both after...
Multi-material incompressible flow simulation using the moment-of-fluid method
Garimella, R V; Schofield, S P; Lowrie, R B; Swartz, B K; Christon, M A; Dyadechko, V
2009-01-01
The Moment-of-Fluid interface reconstruction technique is implemented in a second order accurate, unstructured finite element variable density incompressible Navier-Stokes solver. For flows with multiple materials, MOF significantly outperforms existing first and second order interface reconstruction techniques. For two material flows, the performance of MOF is similar to other interface reconstruction techniques. For strongly driven bouyant flows, the errors in the flow solution dominate and all the interface reconstruction techniques perform similarly.
Kiselev, Alex
Flame Enhancement and Quenching in Fluid Flows Natalia Vladimirovay scale of the flow and laminar front thickness. For cellular flow, we o* *btain v ~ U1=4. We also study(T).* * (1) altered by the fluid flow. Specifically, moderately intense@t o levels of turbulence
Vibration of Wires in Liquid Argon Due to Fluid Flow Kirk T McDonald (kirkmcd@princeton.edu)
McDonald, Kirk
Vibration of Wires in Liquid Argon Due to Fluid Flow Kirk T McDonald (kirkmcd. But in these regions, the Reynolds number of the flow is 56/23 = 2.4, in which case the flow is laminar, not turbulent, and there is no excitation of wire vibration. So, I conclude that wire vibration due to fluid flow is negligible (unless
Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally
Herbert, Bruce
Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally; accepted 14 July 2004; published 14 October 2004. [1] Bedding-parallel permeability of illite-rich shale Geochemistry: Low-temperature geochemistry; KEYWORDS: permeability, shale, fluid chemistry Citation: Kwon, O
On the notion of laminar and weakly turbulent elementary fluid flows: a simple mathematical model
Gianluca Argentini
2006-08-28
An elementary analytical fluid flow is composed by a geometric domain, a list of analytical constraints and by the function which depends on the physical properties, as Reynolds number, of the considered fluid. For this object, notions of laminar or weakly turbulent behavior are described using a simple mathematical model.
Fluid flow and CO2fluidmineral interactions during CO2-storage in sedimentary basins
Cambridge, University of
mineral dissolution rates. Observations from CO2-EOR exper- iments and natural analogues suggestFluid flow and CO2fluidmineral interactions during CO2-storage in sedimentary basins Niko Kampman Natural CO2 analogues Modelling the progress of geochemical processes in CO2 storage sites is frustrated
Temperature distribution in a flowing fluid heated in a microwave resonant cavity
Thomas, J.R. Jr. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Nelson, E.M.; Kares, R.J.; Stringfield, R.M. [Los Alamos National Lab., NM (United States)
1996-04-01
This paper presents results of an analytical study of microwave heating of a fluid flowing through a tube situated along the axis of a cylindrical microwave applicator. The interaction of the microwave field pattern and the fluid velocity profiles is illustrated for both laminar and turbulent flow. Resulting temperature profiles are compared with those generated by conventional heating through a surface heat flux. It is found that microwave heating offers several advantages over conventional heating.
Fe/V Redox Flow Battery Electrolyte Investigation and Optimization
Li, Bin; Li, Liyu; Wang, Wei; Nie, Zimin; Chen, Baowei; Wei, Xiaoliang; Luo, Qingtao; Yang, Zhenguo; Sprenkle, Vincent L.
2013-05-01
Recently invented Fe/V redox flow battery (IVBs) system has attracted more and more attentions due to its long-term cycling stability. In this paper, the factors (such as compositions, state of charge (SOC) and temperatures) influencing the stability of electrolytes in both positive and negative half-cells were investigated by an extensive matrix study. Thus an optimized electrolyte, which can be operated in the temperature ranges from -5oC to 50oC without any precipitations, was identified. The Fe/V flow cells using the optimized electrolytes and low-cost membranes exhibited satisfactory cycling performances at different temperatures. The efficiencies, capacities and energy densities of flow batteries with varying temperatures were discussed in detail.
Spatiotemporal and geometric optimization of sensor arrays for detecting analytes fluids
Lewis, Nathan S.; Freund, Michael S.; Briglin, Shawn M.; Tokumaru, Phil; Martin, Charles R.; Mitchell, David T.
2006-10-17
Sensor arrays and sensor array systems for detecting analytes in fluids. Sensors configured to generate a response upon introduction of a fluid containing one or more analytes can be located on one or more surfaces relative to one or more fluid channels in an array. Fluid channels can take the form of pores or holes in a substrate material. Fluid channels can be formed between one or more substrate plates. Sensor can be fabricated with substantially optimized sensor volumes to generate a response having a substantially maximized signal to noise ratio upon introduction of a fluid containing one or more target analytes. Methods of fabricating and using such sensor arrays and systems are also disclosed.
Spatiotemporal and geometric optimization of sensor arrays for detecting analytes in fluids
Lewis, Nathan S. (La Canada, CA); Freund, Michael S. (Winnipeg, CA); Briglin, Shawn S. (Chittenango, NY); Tokumaru, Phillip (Moorpark, CA); Martin, Charles R. (Gainesville, FL); Mitchell, David (Newtown, PA)
2009-09-29
Sensor arrays and sensor array systems for detecting analytes in fluids. Sensors configured to generate a response upon introduction of a fluid containing one or more analytes can be located on one or more surfaces relative to one or more fluid channels in an array. Fluid channels can take the form of pores or holes in a substrate material. Fluid channels can be formed between one or more substrate plates. Sensor can be fabricated with substantially optimized sensor volumes to generate a response having a substantially maximized signal to noise ratio upon introduction of a fluid containing one or more target analytes. Methods of fabricating and using such sensor arrays and systems are also disclosed.
Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.
2009-01-15
A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.
Pattanayak, S.Ch.; Das, R.K. [Indian Institute of Technology, Kharagpur (India)
1995-12-01
Local void fraction in a vertical cryogenic two-phase flow has been measured with the help of a small capacitance sensor. The time varying capacitance signal of the sensor is used to modulate the pulse width of a multivibrator. The probability distribution function (PDF) of the pulse width data is analysed for identifying the flow regimes, while average pulse width is correlated with the average void fraction. The calibrations of the void fraction sensor are found to be sensitive to the flow regimes. In slug and churn flow regimes the calibrations are also found to be sensitive to fluid flow rates. But no such dependence is observed in bubble and annular flow regimes. The sensitivity towards flow rates could be correlated with the position of PDF peaks of the concerned flow regimes.
Inhomogeneity of fluid flow in Stirling engine regenerators
Jones, J.D. )
1989-10-01
The literature relating to inhomogeneity of flow regenerators is briefly reviewed. It is noted that, in contrast to other applications of regenerators, relatively little attention has been paid to the consequences of flow inhomogeneity for thermal regeneration in Stirling cycle machines. The construction of regenerator capsules for a large stationary Stirling engine is described. A test rig is developed to measure the gas velocity profile across the face of the packed regenerator capsules under steady flow conditions. Measured flow profiles for a number of different matrix materials and construction techniques are presented, and it is noted that stacked-mesh regenerator matrices tend to display marked inhomogeneities of flow. The consequences of flow inhomogeneity for flow friction and regenerator effectiveness are analyzed theoretically, and approximate formulae deduced. One method for reducing flow inhomogeneity in stacked-screen matrice
Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Better understand and model fluid injection into a tight reservoir on the edges of a hydrothermal field. Use seismic data to constrain geomechanical/hydrologic/thermal model of reservoir.
Structure evolution in electrorheological fluids flowing through microchannels
, including valves2,3 , clutches4 and shock absorbers5 . Recently, custom-formulated ER fluids have been that the increasing shear stress passes through three sequential stages17 . In the first stage, the shear stress
Multiphase flow and control of fluid path in microsystems
Jhunjhunwala, Manish
2005-01-01
Miniaturized chemical-systems are expected to have advantages of handling, portability, cost, speed, reproducibility and safety. Control of fluid path in small channels between processes in a chemical/biological network ...
Fluid Flow Property Estimation from Seismic Scattering Data
Brown, Stephen
2012-01-01
We present a methodology for relating seismic scattering signals from fractures to the fluid permeability field of the fracture network. The workflow is used to interpret seismic scattering signals for the reservoir ...
Numerical simulations of stratified fluid flow over topography near resonance
Brown, Harmony Rose
2008-01-01
tidal ?ow over isolated topography. Deep Sea Research II,strati?ed ?uid ?ow over topography. J. Fluid Mech. , [22] I.strati?ed ?uid ?ow over topography near resonance A thesis
Robust processing of optical flow of fluids Ashish Doshi and Adrian G. Bors, Senior Member, IEEE
Bors, Adrian
to the change of illumination, image noise and the perspective projection when representing a 3-D scene in a 2-D1 Robust processing of optical flow of fluids Ashish Doshi and Adrian G. Bors, Senior Member, IEEE changing patterns which poses chal- lenges to existing optical flow estimation methods. The proposed
Two-fluid flowing equilibria of compact plasmas Loren C. Steinhauer
Washington at Seattle, University of
Two-fluid flowing equilibria of compact plasmas Loren C. Steinhauer Redmond Plasma Physics by limiting attention to compact toroids in a ``stationary-energy'' state with uniform density. Flowing. © 2001 American Institute of Physics. DOI: 10.1063/1.1388034 I. INTRODUCTION In magnetic fusion the need
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1
Minkoff, Susan E.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1 reservoir properties. Pore pressures from flow are used as loads for the geomechanics code-505-844-9297. 2 Fax: +1-512-232-2445. www.elsevier.com/locate/jpetscieng Journal of Petroleum Science
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids
Natelson, Douglas
2005-01-01
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids G, USA Received 10 September 2004; received in revised form 23 July 2005 Abstract Roll coating to a substrate. Except at low speed, the two-dimensional film splitting flow that occurs in forward roll coating
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Paris-Sud XI, Université de
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur
Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Marchese, Francis
Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Bahrami, Majid
Viscous Flow in Ducts We want to study the viscous flow in ducts with various velocities, fluids and duct shapes. The basic problem is this: Given the pipe geometry and its added components (e Fluid Mechanics (S 09) Viscous Flow in Ducts 2 103
Ortiz, Marcos German (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
1998-01-01
A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.
Ortiz, M.G.; Boucher, T.J.
1998-10-27
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-13
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
Modeling Fluid Flow in Natural Systems, Model Validation and...
Broader source: Energy.gov (indexed) [DOE]
approach places constraints on the generation of the DFN, and permits creation of high-quality computational meshes that enable accurate flow and transport solutions on the...
Using Genetic Algorithms to Optimize Social Robot Behavior for Improved Pedestrian Flow
Maciejewski, Anthony A. "Tony"
Using Genetic Algorithms to Optimize Social Robot Behavior for Improved Pedestrian Flow Bryce D pedestrian flow. In this case, a genetic algorithm is applied to find the optimal parameters to a crowded situation can result in significant improvement in pedestrian flow. Using the optimized values
PAPER B3: PHYSICS OF FLUID FLOWS Hilary Term 2010
Read, Peter L.
systems · Industry e.g. gases in pipes, polymer flows · Oil extraction liquids flowing through: This defines a `local' . Similar for `local' temperature, velocity, etc. (NB: exclude gases at very low pressure.) [For molecular fluctuations, see Blundell and Blundell, Thermal Physics, p. 375, eq.(33.56): rms
Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates
Ober, Thomas J. (Thomas Joseph)
2013-01-01
We combine pressure, velocimetry and birefringence measurements to study three phenomena for which the fluid rheology plays a dominant role: 1) shear banding in micellar fluids, 2) extension-dominated flows in microfluidic ...
Resistive Network Optimal Power Flow: Uniqueness and Algorithms
Tan, CW; Cai, DWH; Lou, X
2015-01-01
The optimal power flow (OPF) problem minimizes the power loss in an electrical network by optimizing the voltage and power delivered at the network buses, and is a nonconvex problem that is generally hard to solve. By leveraging a recent development on the zero duality gap of OPF, we propose a second-order cone programming convex relaxation of the resistive network OPF, and study the uniqueness of the optimal solution using differential topology, especially the Poincare-Hopf Index Theorem. We characterize the global uniqueness for different network topologies, e.g., line, radial, and mesh networks. This serves as a starting point to design distributed local algorithms with global behaviors that have low complexity, are computationally fast, and can run under synchronous and asynchronous settings in practical power grids.
Optimal Control of Transient Flow in Natural Gas Networks
Zlotnik, Anatoly; Backhaus, Scott
2015-01-01
We outline a new control system model for the distributed dynamics of compressible gas flow through large-scale pipeline networks with time-varying injections, withdrawals, and control actions of compressors and regulators. The gas dynamics PDE equations over the pipelines, together with boundary conditions at junctions, are reduced using lumped elements to a sparse nonlinear ODE system expressed in vector-matrix form using graph theoretic notation. This system, which we call the reduced network flow (RNF) model, is a consistent discretization of the PDE equations for gas flow. The RNF forms the dynamic constraints for optimal control problems for pipeline systems with known time-varying withdrawals and injections and gas pressure limits throughout the network. The objectives include economic transient compression (ETC) and minimum load shedding (MLS), which involve minimizing compression costs or, if that is infeasible, minimizing the unfulfilled deliveries, respectively. These continuous functional optimiza...
Scalability of preconditioners as a strategy for parallel computation of compressible fluid flow
Hansen, G.A.
1996-05-01
Parallel implementations of a Newton-Krylov-Schwarz algorithm are used to solve a model problem representing low Mach number compressible fluid flow over a backward-facing step. The Mach number is specifically selected to result in a numerically {open_quote}stiff{close_quotes} matrix problem, based on an implicit finite volume discretization of the compressible 2D Navier-Stokes/energy equations using primitive variables. Newton`s method is used to linearize the discrete system, and a preconditioned Krylov projection technique is used to solve the resulting linear system. Domain decomposition enables the development of a global preconditioner via the parallel construction of contributions derived from subdomains. Formation of the global preconditioner is based upon additive and multiplicative Schwarz algorithms, with and without subdomain overlap. The degree of parallelism of this technique is further enhanced with the use of a matrix-free approximation for the Jacobian used in the Krylov technique (in this case, GMRES(k)). Of paramount interest to this study is the implementation and optimization of these techniques on parallel shared-memory hardware, namely the Cray C90 and SGI Challenge architectures. These architectures were chosen as representative and commonly available to researchers interested in the solution of problems of this type. The Newton-Krylov-Schwarz solution technique is increasingly being investigated for computational fluid dynamics (CFD) applications due to the advantages of full coupling of all variables and equations, rapid non-linear convergence, and moderate memory requirements. A parallel version of this method that scales effectively on the above architectures would be extremely attractive to practitioners, resulting in efficient, cost-effective, parallel solutions exhibiting the benefits of the solution technique.
Single-cycle mixed-fluid LNG process Part II: Optimal operation
Skogestad, Sigurd
consider Case 8 from part I, where a liquid turbine is included both in the expansion of natural gas of natural gas and it has been optimized in several publications (Lee et al., 2002; Del Nogal et al., 2005: rotational speed 4 Cooler: flow of sea water (SW) in cooler 5 Load: Feed flow of natural gas (can also
Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal...
section of the 0.6-Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix...
Numerical simulation of flow separation control by oscillatory fluid injection
Resendiz Rosas, Celerino
2005-08-29
In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous...
Jong Chull Jo; Myung Jo Jhung; Woong Sik Kim; Hho Jung Kim
2004-07-01
This study investigates the fluid-elastic instability characteristics of steam generator helical type tubes in operating nuclear power plants. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Investigated are the effects of the helix angle, the number of supports and the status of the inner fluid on the modal, and fluid-elastic instability characteristics of the tubes, which are expressed in terms of the natural frequency, corresponding mode shape, and stability ratio. (authors)
Finite-time barriers to front propagation in two-dimensional fluid flows
Mahoney, John R
2015-01-01
Recent theoretical and experimental investigations have demonstrated the role of certain invariant manifolds, termed burning invariant manifolds (BIMs), as one-way dynamical barriers to reaction fronts propagating within a flowing fluid. These barriers form one-dimensional curves in a two-dimensional fluid flow. In prior studies, the fluid velocity field was required to be either time-independent or time-periodic. In the present study, we develop an approach to identify prominent one-way barriers based only on fluid velocity data over a finite time interval, which may have arbitrary time-dependence. We call such a barrier a burning Lagrangian coherent structure (bLCS) in analogy to Lagrangian coherent structures (LCSs) commonly used in passive advection. Our approach is based on the variational formulation of LCSs using curves of stationary "Lagrangian shear", introduced by Farazmand, Blazevski, and Haller [Physica D 278-279, 44 (2014)] in the context of passive advection. We numerically validate our techniqu...
Single-cycle mixed-fluid LNG process Part II: Optimal operation
Skogestad, Sigurd
Single-cycle mixed-fluid LNG process Part II: Optimal operation Jørgen Bauck Jensen and Sigurd of work that goes into the design of LNG processes, there is surprisingly little attention simple LNG process, namely the PRICO process. Keywords: PRICO, LNG, operation 1 Introduction The process
Rutqvist, J.
2014-01-01
and Mining Sciences & Geomechanics Abstracts, 1983, 20:and Mining Sciences & Geomechanics Abstracts, 1985, BerrymanL W. Coupling fluid flow and geomechanics in dual-porosity
Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction
Lemoff, Asuncion V. (Union City, CA); Lee, Abraham P. (Irvine, CA)
2010-07-13
A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.
Fluid-particle flow modelling and validation using two-way-coupled mesoscale SPH-DEM
Robinson, Martin; Ramaioli, Marco
2013-01-01
We present a meshless simulation method for multiphase fluid-particle flows coupling Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM). Rather than fully resolving the interstitial fluid, which is often infeasible, the unresolved fluid model is based on the locally averaged Navier Stokes equations, which are coupled with a DEM model for the solid phase. In contrast to similar mesh-based Discrete Particle Methods (DPMs), this is a purely particle-based method and enjoys the flexibility that comes from the lack of a prescribed mesh. It is suitable for problems such as free surface flow or flow around complex, moving and/or intermeshed geometries. It can be used for both one and two-way coupling and is applicable to both dilute and dense particle flows. A comprehensive validation procedure for fluid-particle simulations is presented and applied to the SPH-DEM method, using simulations of single and multiple particle sedimentation in a 3D fluid column and comparison with analytical model...
Impact of Turbulence Closures and Numerical Errors for the Optimization of Flow Control Devices
Paris-Sud XI, Université de
Impact of Turbulence Closures and Numerical Errors for the Optimization of Flow Control Devices J the use of a Kriging-based global optimization method to determine optimal control parameters conduct an optimization process and measure the impact of numerical and modeling errors on the optimal
Hamel, William R. (Farragut, TN)
1984-01-01
This invention relates to a new method and new apparatus for determining fluid mass flowrate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flowrate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flowrate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flowrate and density are determined from the required change in power input. The invention provides stable, rapid, and accurate measurements. It does not require bending of the fluid flow.
Study of shear-driven unsteady flows of a fluid with a pressure dependent viscosity
Srinivasan, Shriram
2009-05-15
-DRIVEN UNSTEADY FLOWS OF A FLUID WITH A PRESSURE DEPENDENT VISCOSITY A Thesis by SHRIRAM SRINIVASAN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE December 2008 Major... Subject: Mechanical Engineering STUDY OF SHEAR-DRIVEN UNSTEADY FLOWS OF A FLUID WITH A PRESSURE DEPENDENT VISCOSITY A Thesis by SHRIRAM SRINIVASAN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements...
Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids
I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis
2007-12-11
Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component of wave-vector along the equilibrium velocity. These results suggest that all non-symmetric instabilities in ideal MHD systems with flows are associated with coupling of positive and negative energy waves. As an example the energy of eigen-modes is calculated for incompressible conducting fluid rotating in axial magnetic field.
Medizade, Masoud (San Luis Obispo, CA); Ridgely, John Robert (Los Osos, CA)
2009-12-15
An arrangement which utilizes an inexpensive flap valve/flow transducer combination and a simple local supervisory control system to monitor and/or control the operation of a positive displacement pump used to extract petroleum from geologic strata. The local supervisory control system controls the operation of an electric motor which drives a reciprocating positive displacement pump so as to maximize the volume of petroleum extracted from the well per pump stroke while minimizing electricity usage and pump-off situations. By reducing the electrical demand and pump-off (i.e., "pounding" or "fluid pound") occurrences, operating and maintenance costs should be reduced sufficiently to allow petroleum recovery from marginally productive petroleum fields. The local supervisory control system includes one or more applications to at least collect flow signal data generated during operation of the positive displacement pump. No flow, low flow and flow duration are easily evaluated using the flap valve/flow transducer arrangement.
Quantum Simulator for Transport Phenomena in Fluid Flows
Mezzacapo, A; Lamata, L; Egusquiza, I L; Succi, S; Solano, E
2015-01-01
Transport phenomena are one of the most challenging problems in computational physics. We present a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics problems within a lattice kinetic formalism. This quantum simulator is obtained by exploiting the analogies between Dirac and lattice Boltzmann equations. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors.
Quantum Simulator for Transport Phenomena in Fluid Flows
A. Mezzacapo; M. Sanz; L. Lamata; I. L. Egusquiza; S. Succi; E. Solano
2015-08-19
Transport phenomena still stand as one of the most challenging problems in computational physics. By exploiting the analogies between Dirac and lattice Boltzmann equations, we develop a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics transport phenomena within a lattice kinetic formalism. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors.
Reciprocity Relations Between Stokes Flows of Viscous and Viscoelastic Fluids
Klapper, Isaac
- terpretation: a prescribed velocity on a translating sphere [24, 13, 7] and a stationary point source of force relations, sphere forcing, forced flow. 2 #12;1 Introduction Linear response theory (of thermal fluctuations of slip of the sphere, and inertial effects. They derived the generalized Stokes-Einstein drag law
Coupling of Fluid Flow and Deformation in Underground Formations
This paper demonstrates the necessity of using the coupled Biot's equations for deformation-flow problems in ..... For most soils Ks is much larger than the bulk modulus K of .... Due to the stiffness and bending of the overburden, the reservoir.
NUMERICAL MODELING OF FLUID FLOW AND TIME-LAPSE ...
gabriela
CO2 injection operation at the Sleipner gas field in the North Sea, operated by Statoil ... The simultaneous flow of brine and CO2 is modeled with the Black-Oil formulation for ..... As water saturation is reduced, and the larger pores drained first, ...
FLUID FLOW AND PARTICLE DEPOSITION SIMULATIONS IN THE HUMAN NOSE
Reimers, Martin
Nose AS) developing a patented concept for efficient nasal delivery of drugs and vaccines. The objective- filled spaces, i.e. the sinuses. The olfactory mucosa #12;is situated in the roof of the nasal cavity and vaccines. The narrow flow passages offer many challenges for efficient nasal delivery of drugs and vaccines
Urs Zimmermann; Frank Smallenburg; Hartmut Löwen
2015-12-02
Using both dynamical density functional theory and particle-resolved Brownian dynamics simulations, we explore the flow of two-dimensional colloidal solids and fluids driven through a linear channel with a geometric constriction. The flow is generated by a constant external force acting on all colloids. The initial configuration is equilibrated in the absence of flow and then the external force is switched on instantaneously. Upon starting the flow, we observe four different scenarios: a complete blockade, a monotonic decay to a constant particle flux (typical for a fluid), a damped oscillatory behaviour in the particle flux, and a long-lived stop-and-go behaviour in the flow (typical for a solid). The dynamical density functional theory describes all four situations but predicts infinitely long undamped oscillations in the flow which are always damped in the simulations. We attribute the mechanisms of the underlying stop-and-go flow to symmetry conditions on the flowing solid. Our predictions are verifiable in real-space experiments on magnetic colloidal monolayers which are driven through structured microchannels and can be exploited to steer the flow throughput in microfluidics.
Exact Convex Relaxation of Optimal Power Flow in Radial Networks
Gan, LW; Li, N; Topcu, U; Low, SH
2015-01-01
The optimal power flow (OPF) problem determines a network operating point that minimizes a certain objective such as generation cost or power loss. It is nonconvex. We prove that a global optimum of OPF can be obtained by solving a second-order cone program, under a mild condition after shrinking the OPF feasible set slightly, for radial power networks. The condition can be checked a priori, and holds for the IEEE 13, 34, 37, 123-bus networks and two real-world networks.
MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS
Stanford University
MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS for t h e i n - s i t u measurement of water content i n porous media, expressed as a volume f r a c t i o n of t h e pore space; ( 2 ) t o measure water content i n t h e two-phase geothermal f l u i d flow
Michael R. Gross; Kajari Ghosh; Alex K. Manda; Sumanjit Aich
2006-05-08
The theory behind how chemically reactive tracers are used to characterize the velocity and temperature distribution in steady flowing systems is reviewed. Kinetic parameters are established as a function of reservoir temperatures and fluid residence times for selecting appropriate reacting systems. Reactive tracer techniques are applied to characterize the temperature distribution in a laminar-flow heat exchanger. Models are developed to predict reactive tracer behavior in fractured geothermal reservoirs of fixed and increasing size.
Model Reduction of Turbulent Fluid Flows Using the Supply Rate
Sharma, A S
2013-01-01
A method for finding reduced-order approximations of turbulent flow models is presented. The method preserves bounds on the production of turbulent energy in the sense of the $\\curly{L}_2$ norm of perturbations from a notional laminar profile. This is achieved by decomposing the Navier-Stokes system into a feedback arrangement between the linearised system and the remaining, normally neglected, nonlinear part. The linear system is reduced using a method similar to balanced truncation, but preserving bounds on the supply rate. The method involves balancing two algebraic Riccati equations. The bounds are then used to derive bounds on the turbulent energy production. An example of the application of the procedure to flow through a long straight pipe is presented. Comparison shows that the new method approximates the supply rate at least as well as, or better than, canonical balanced truncation.
Multiscale Simulation Framework for Coupled Fluid Flow and Mechanical Deformation
Tchelepi, Hamdi
2014-11-14
A multiscale linear-solver framework for the pressure equation associated with flow in highly heterogeneous porous formations was developed. The multiscale based approach is cast in a general algebraic form, which facilitates integration of the new scalable linear solver in existing flow simulators. The Algebraic Multiscale Solver (AMS) is employed as a preconditioner within a multi-stage strategy. The formulations investigated include the standard MultiScale Finite-Element (MSFE) andMultiScale Finite-Volume (MSFV) methods. The local-stage solvers include incomplete factorization and the so-called Correction Functions (CF) associated with the MSFV approach. Extensive testing of AMS, as an iterative linear solver, indicate excellent convergence rates and computational scalability. AMS compares favorably with advanced Algebraic MultiGrid (AMG) solvers for highly detailed three-dimensional heterogeneous models. Moreover, AMS is expected to be especially beneficial in solving time-dependent problems of coupled multiphase flow and transport in large-scale subsurface formations.
Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using
Stanford University
Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using Simultaneous;Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using Simultaneous Pseudo Abstract. The paper presents numerical results of optimized airfoils at ultra-low Reynolds numbers
Abdou, Mohamed
2007-01-01
Fusion Engineering and Design 82 (2007) 22172225 Integrated thermo-fluid analysis towards helium Engineering and Design 82 (2007) 22172225 This calls in for an extensive analysis of the various proposed flow path design for an ITER solid breeder blanket module A. Yinga,, M. Narulaa, R. Hunta, M. Abdoua, Y
Nearby-fluids equilibria. II. Zonal flows in a high-, self-organized plasma experiment
Washington at Seattle, University of
Nearby-fluids equilibria. II. Zonal flows in a high- , self-organized plasma experiment L. C. Steinhauera and H. Y. Guo University of Washington, Redmond Plasma physics Laboratory, Redmond, Washington structure observed in a high- field reversed configuration FRC produced in the translation, confinement
Wake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa)
Liepmann, Dorian
counterpart is made by a drag correction factor, K FD 6 0aUt , 3 where FD is the drag force on the sphere which balances the force due to gravity, ( s f)*( 4 3 ga3 ). The drag correc- tion factor is, in generalWake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa) Department
Numerical modeling of fluid flow and time-lapse seismograms applied to
Santos, Juan
; and CO2 and CO2 are the CO2 mole fraction and the CO2 mass fraction in the brine phase. This conversionNumerical modeling of fluid flow and time-lapse seismograms applied to CO2 storage and monitoring G and time-lapse seismograms applied to CO2 storage and monitoring p. #12;Introduction · Fossil
Gent, Universiteit
of the study is to study internal processes of porous geomaterials by analysis the pore structure in 2D and 3D geomaterials, fluid flow, modelling, optical microscopy and 3D image analysis. Promotor: Prof. Dr. Veerle of the geological material. Petrographical research with optical and fluorescence microscopy and SEM. Non
Goal{Oriented A Posteriori Error Estimation for Compressible Fluid Flows
Hartmann, Ralf
Goal{Oriented A Posteriori Error Estimation for Compressible Fluid Flows Ralf Hartmann 1;? and Paul-69120 Heidelberg, Germany. e-mail: Ralf.Hartmann@iwr.uni-heidelberg.de 2 Department of Mathematics of Heidelberg ?? Paul Houston acknowledges the #12;nancial support of the EPSRC (GR/N24230). #12; 2 R. Hartmann
Incompressible Multiphase flow and Encapsulation simulations using the moment of fluid method 1
Sussman, Mark
, spray cooling, icing, combustion and agricultural irrigation. The instability of the interface, mass, it is still very difficult to capture the detailed flow fields. Computational fluid dynamics (CFD) has, stress fields, and vorticity are easily extracted from CFD simulations. Three major challenges exist
CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke
Snooke, Neal
M2 CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke Department- oped on top of the MCIRQ simulator with the aim to produce an automated FMEA for aircraft fuel systems similar to pre- viously developed automated electrical FMEA. Introduction This paper describes a circuit
FLOW OF A FLUID THROUGH A POROUS SOLID DUE TO HIGH PRESSURE GRADIENTS
Bonito, Andrea
applications involving the flow of fluids through a porous media, like the problems of enhanced oil recovery technical problem where such high pressure differentials are involved is that of extracting unconventional oil deposits such as shale which is becoming ever so important now. In this study, we show
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow
Wang, Chao-Yang
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow W-dimensional model is developed to simulate discharge of a primary lithium/thionyl chloride battery. The model to the first task with important examples of lead-acid,1-3 nickel-metal hydride,4-8 and lithium-based batteries
Coating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits
is on viscoelastic effects on single roll coating at low dimensionless speeds, although the analytical results weCoating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits J. Ashmore(1,a), A February 2007 Abstract. We present an asymptotic analysis of the thickness of the liquid film that coats
Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems
Ingram, David
of high velocity air which in turn drives a turbine also involves the flows of both water and air domain encompasses both water and air regions and the interface between the two fluids is treated; Free surface; Air water interaction. Introduction The development of numerical methods which
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
Dynamics of a confined dusty fluid in a sheared ion flow
Laishram, Modhuchandra; Sharma, Devendra; Kaw, Predhiman K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2014-07-15
Dynamics of an isothermally driven dust fluid is analyzed which is confined in an azimuthally symmetric cylindrical setup by an effective potential and is in equilibrium with an unconfined sheared flow of a streaming plasma. Cases are analyzed where the confining potential constitutes a barrier for the driven fluid, limiting its spatial extension and boundary velocity. The boundary effects entering the formulation are characterized by applying the appropriate boundary conditions and a range of solutions exhibiting single and multiple vortex are obtained. The equilibrium solutions considered in the cylindrical setup feature a transition from single to multiple vortex state of the driven flow. Effects of (i) the variation in dust viscosity, (ii) coupling between the driving and the driven fluid, and (iii) a friction determining the equilibrium dynamics of the driven system are characterized.
Dependence of fluid flows in an evaporating sessile droplet on the characteristics of the substrate
Barash, L Yu
2014-01-01
Temperature distributions and the corresponding vortex structures in an evaporating sessile droplet are obtained by performing detailed numerical calculations. A Marangoni convection induced by thermal conduction processes in the drop and the substrate is demonstrated to be able to result not only in a single vortex, but also in two or three vortices, depending on the ratio of substrate to fluid thermal conductivities, on the substrate thickness and the contact angle. The "phase diagrams" containing information on the number, orientation and spatial location of the vortices for quasistationary fluid flows are presented and analysed. The results obtained demonstrate that the fluid flow structure in evaporating droplets can be influenced in a controlled manner by selecting substrates with appropriate properties.
Grujicic, Mica
Suitability of boron-nitride single-walled nanotubes as fluid-flow conduits in nano-valve the suitability of boron-nitride single-walled nanotubes (SWNTs) as fluid- flow conduits in the nano-valve reserved. doi:10.1016/j.apsusc.2004.11.007 #12;control nano-valve based on a silicon nano-beam actuator
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid
Attard, Phil
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid March 2005; accepted 4 May 2005; published online 28 June 2005 A statistical mechanical theory for heat distribution for heat flow down an imposed thermal gradient is tested with simulations of a Lennard-Jones fluid
Xenophontos, Christos
2007-01-01
in the petroleum industry often operates with viscoplastic fluids, such as drilling muds exhibit- ing a yieldJ. Non-Newtonian Fluid Mech. 142 (2007) 135142 Cessation of annular Poiseuille flows of Bingham fields were represented from the flow of avalanches to those of gels. In particular, a drilling equipment
Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
Ortiz, M.G.
1998-02-10
A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
Ortiz, Marcos German (Idaho Falls, ID)
1998-01-01
A system for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.
Primary pump power as a measure of fluid density during bubbly two-phase flow. [PWR
McCreery, G.E.; Linebarger, J.H.; Koske, J.E.
1983-01-01
A nuclear plant operator requires other information on reactor coolant system inventory besides just pressurizer liquid level, which often disappears or gives ambiguous indications during a loss-of-coolant accident. Erroneous instrument readings during the Three Mile Island and Ginna accidents are examples. Pump power or current is shown in this paper to provide an additional source of inventory information. When the reactor coolant pumps are operating, it allows the operator to make decisions about the advisability of continued pump- and safety-injection operation. The inventory information is provided by a simple method of calculating fluid density for bubbly two-phase flow by relating pump power or current to fluid density. The calculational method is derived and compared with data in this paper. Calculations using the method agree well with the measured experimental data with increasing void fraction, until the flow transitions from bubbly to partially stratified churn flow within the pump.
OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS
Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto
2001-09-04
It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.
Non-Invasive Characterization Of A Flowing Multi-Phase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
2005-11-01
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Armstrong, William D. (Laramie, WY); Naughton, Jonathan (Laramie, WY); Lindberg, William R. (Laramie, WY)
2008-09-02
A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.
SALE: a simplified ALE computer program for fluid flow at all speeds
Amsden, A.A.; Ruppel, H.M.; Hirt, C.W.
1980-06-01
A simplified numerical fluid-dynamics computing technique is presented for calculating two-dimensional fluid flows at all speeds. It combines an implicit treatment of the pressure equation similar to that in the Implicit Continuous-fluid Eulerian (ICE) technique with the grid rezoning philosophy of the Arbitrary Lagrangian-Eulerian (ALE) method. As a result, it can handle flow speeds from supersonic to the incompressible limit in a grid that may be moved with the fluid in typical Lagrangian fashion, or held fixed in an Eulerian manner, or moved in some arbitrary way to give a continuous rezoning capability. The report describes the combined (ICEd-ALE) technique in the framework of the SALE (Simplified ALE) computer program, for which a general flow diagram and complete FORTRAN listing are included. A set of sample problems show how to use or modify the basic code for a variety of applications. Numerical listings are provided for a sample problem run with the SALE program.
Optimal Power Flow of Multiple Energy Carriers(Geidl and Andersson...
signal, optimal power flow and economic dispatch The proposed method stabilized the power grid, reduced the marginal cost of electricity, and increased the marginal cost of...
A turnstile mechanism for fronts propagating in fluid flows
John R. Mahoney; Kevin A. Mitchell
2013-05-22
We consider the propagation of fronts in a periodically driven flowing medium. It is shown that the progress of fronts in these systems may be mediated by a turnstile mechanism akin to that found in chaotic advection. We first define the modified ("active") turnstile lobes according to the evolution of point sources across a transport boundary. We then show that the lobe boundaries may be constructed from stable and unstable \\emph{burning invariant manifolds}---one-way barriers to front propagation analogous to traditional invariant manifolds for passive advection. Because the burning invariant manifolds (BIMs) are one-dimensional curves in a three-dimensional ($xy\\theta$) phase space, their projection into $xy$-space exhibits several key differences from their advective counterparts: (lobe) areas are not preserved, BIMs may self-intersect, and an intersection between stable and unstable BIMs does not map to another such intersection. These differences must be accommodated in the correct construction of the new turnstile. As an application, we consider a lobe-based treatment protocol for protecting an ocean bay from an invading algae bloom.
King, Bradley Donald
2013-12-31
A diagenetic study of the Cambrian-Ordovician Arbuckle Group to the Middle Pennsylvanian Cherokee Group in south-central Kansas produced evidence of regional advective fluid flow and more localized fracture-controlled fluid flow affecting porosity...
Particle-fluid-structure interaction for debris flow impact on flexible barriers
A. Leonardi; F. K. Wittel; M. Mendoza; R. Vetter; H. J. Herrmann
2014-09-29
Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, a numerical tool for rational design of such structures is still missing. In this work, a hybrid computational framework is presented, using a total Lagrangian formulation of the Finite Element Method (FEM) to represent a flexible barrier. The actions exerted on the structure by a debris flow are obtained from simultaneous simulations of the flow of a fluid-grain mixture, using two conveniently coupled solvers: the Discrete Element Method (DEM) governs the motion of the grains, while the free-surface non-Newtonian fluid phase is solved using the Lattice-Boltzmann Method (LBM). Simulations on realistic geometries show the dependence of the momentum transfer on the barrier on the composition of the debris flow, challenging typical assumptions made during the design process today. In particular, we demonstrate that both grains and fluid contribute in a non-negligible way to the momentum transfer. Moreover, we show how the flexibility of the barrier reduces its vulnerability to structural collapse, and how the stress is distributed on its fabric, highlighting potential weak points.
Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)
1999-01-01
Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.
Fluid flow modeling of resin transfer molding for composite material wind turbine blade structures.
Cairns, Douglas S. (Montana State University, Bozeman, MT); Rossel, Scott M. (Montana State University, Bozeman, MT)
2004-06-01
Resin transfer molding (RTM) is a closed mold process for making composite materials. It has the potential to produce parts more cost effectively than hand lay-up or other methods. However, fluid flow tends to be unpredictable and parts the size of a wind turbine blade are difficult to engineer without some predictive method for resin flow. There were five goals of this study. The first was to determine permeabilities for three fabrics commonly used for RTM over a useful range of fiber volume fractions. Next, relations to estimate permeabilities in mixed fabric lay-ups were evaluated. Flow in blade substructures was analyzed and compared to predictions. Flow in a full-scale blade was predicted and substructure results were used to validate the accuracy of a full-scale blade prediction.
The flow of power law fluids in elastic networks and porous media
Sochi, Taha
2015-01-01
The flow of power law fluids, which include shear thinning and shear thickening as well as Newtonian as a special case, in networks of interconnected elastic tubes is investigated using a residual based pore scale network modeling method with the employment of newly derived formulae. Two relations describing the mechanical interaction between the local pressure and local cross sectional area in distensible tubes of elastic nature are considered in the derivation of these formulae. The model can be used to describe shear dependent flows of mainly viscous nature. The behavior of the proposed model is vindicated by several tests in a number of special and limiting cases where the results can be verified quantitatively or qualitatively. The model, which is the first of its kind, incorporates more than one major non-linearity corresponding to the fluid rheology and conduit mechanical properties, that is non-Newtonian effects and tube distensibility. The formulation, implementation and performance indicate that the...
TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems
Moridis, G.J.; Pruess (editor), K.
1992-11-01
The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.
Porosity, permeability and fluid flow in the YellowstoneGeothermal System, Wyoming
Dobson, Patrick F.; Kneafsey, Timothy J.; Hulen, Jeffrey; Simmons, Ardyth
2002-03-29
Cores from two of 13 U.S. Geological Survey (USGS) research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Porosity and matrix permeability measurements and petrographic examination of the cores were used to evaluate the effects of lithology and hydrothermal alteration on porosity and permeability. The intervals studied in these two core holes span the conductive zone and the upper portion of the convective geothermal reservoir. Variations in porosity and matrix permeability observed in the Y-5 and Y-8 cores are primarily controlled by lithology. Y-8 intersects three distinct lithologies: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous ash-flow tuff. The sandstone typically has high permeability and porosity, and the tuff has very high porosity and moderate permeability, while the perlitic lava has very low porosity and is essentially impermeable. Hydrothermal self-sealing appears to have generated localized permeability barriers within the reservoir. Changes in pressure and temperature in Y-8 correspond to a zone of silicification in the volcaniclastic sandstone just above the contact with the perlitic rhyolite; this silicification has significantly reduced porosity and permeability. In rocks with inherently low matrix permeability (such as densely welded ash-flow tuff), fluid flow is controlled by the fracture network. The Y-5 core hole penetrates a thick intracaldera section of the0.6 Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix permeability, and the frequency of fractures and veins. Fractures are most abundant within the more densely welded sections of the tuff. However, the most prominent zones of fracturing and mineralization are associated with hydrothermal breccias within densely welded portions of the tuff. These breccia zones represent transient conduits of high fluid flow that formed by the explosive release of overpressure in the underlying geothermal reservoir and that were subsequently sealed by supersaturated geothermal fluids. In addition to this fracture sealing, hydrothermal alteration at Yellowstone appears generally to reduce matrix permeability and focus flow along fractures, where multiple pulses of fluid flow and self-sealing have occurred.
Haghshenas, Arash
2013-04-24
The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster...
Chevarunotai, Natasha
2014-11-13
temperature alteration in the reservoir. In this study, we developed a robust analytical model to estimate the flowing-fluid-temperature distribution in the reservoir accounting for J-T heating or cooling effect. All significant heat-transfer mechanisms...
Yang, Cher-Chiang
2008-05-05
imagine how the stall occurs over an airfoil or how the turbulent air looks like after separation happens. In this case, a (flow separation) picture will definitely speak more than a thousand words (or equations). Computational Fluid Dynamics offers...
Harstad, H. [New Mexico Tech, Socorro, NM (United States); Teufel, L.W.; Lorenz, J.C.; Brown, S.R. [Sandia National Labs., Albuquerque, NM (United States). Geomechanics Dept.
1996-08-01
Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions
Ferrari, Jerome
2009-01-01
The evaluation of fluid forces on the stem is important for wear prediction of valve and actuator guidance parts. While estimating the axial load is straight forward, estimating and/or measuring the side load is more difficult, especially for globe valves. Therefore, measurements are carried out on an ad hoc, scale 1, model of a 2" globe valve. The body is replicated in Plexiglas to enable flow visualization and the original stem is heavily instrumented to allow force measurements in every direction. The flow loop facility used for this experiment is designed to allow fine-tuning of the cavitation intensity. The experiment is run for a set of cavitation conditions, flow rates and disc positions. The results show that the transverse force (perpendicular to the stem) can reach the order of the axial force; thus it should not be ignored. We also observed that it depends very weakly on the cavitation levels. Videos made with a high-speed camera allow an interesting understanding of the fluid flow and the cavitati...
Fossen, Haakon
Deformation bands and their impact on fluid flow in sandstone reservoirs: the role of natural Cataclastic deformation bands, which are common in sandstone reservoirs and which may negatively affect fluid simulation of an array of cataclastic deformation bands in Cretaceous sandstones in in the Bassin de Sud
Nikoleris, Teo
1988-01-01
NUMERICAL SIMULATION OF THE NON-ISOTHERMAL DEVELOPING FLOXV OF A NONLINEAR VISCOELASTIC FLUID IN A RECTANGULAR CHANNEL A Thesis by TEO NIKOLERIS Submitted to the Graduate College of Texas A&M University in partial fulfillment... developing flow of a nonlinear viscoelas- tic fluid. The temperature dependence of the rheological parameters was imposed using an Arrhenius-like exponential relationship. The flow was creeping, at the early stages of thermal development and wall cooling...
Donald M. McEligot; Stefan Becker; Hugh M. McIlroy, Jr.
2010-07-01
In recent international collaboration, INL and Uni. Erlangen have developed large MIR flow systems which can be ideal for joint graduate student education and research. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages and around objects to be obtained without locating a disturbing transducer in the flow field and without distortion of the optical paths. The MIR technique is not new itself; others employed it earlier. The innovation of these MIR systems is their large size relative to previous experiments, yielding improved spatial and temporal resolution. This report will discuss the benefits of the technique, characteristics of the systems and some examples of their applications to complex situations. Typically their experiments have provided new fundamental understanding plus benchmark data for assessment and possible validation of computational thermal fluid dynamic codes.
Fluid dynamic propagation of initial baryon number perturbations on a Bjorken flow background
Floerchinger, Stefan
2015-01-01
Baryon number density perturbations offer a possible route to experimentally measure baryon number susceptibilities and heat conductivity of the quark gluon plasma. We study the fluid dynamical evolution of local and event-by-event fluctuations of baryon number density, flow velocity and energy density on top of a (generalised) Bjorken expansion. To that end we use a background-fluctuation splitting and a Bessel-Fourier decomposition for the fluctuating part of the fluid dynamical fields with respect to the azimuthal angle, the radius in the transverse plane and rapidity. We examine how the time evolution of linear perturbations depends on the equation of state as well as on shear viscosity, bulk viscosity and heat conductivity for modes with different azimuthal, radial and rapidity wave numbers. Finally we discuss how this information is accessible to experiments in terms of the transverse and rapidity dependence of correlation functions for baryonic particles in high energy nuclear collisions.
Optimal Power Flow Formulation in Market of Retail Wheeling Taiyou Yong, Student Member, IEEE distribution in the new retail wheeling market. Formation of optimal power flow (OPF) problem, in which concerns on optimal power flow arise in the retail wheeling market. In the deregulated power system
Othman, M. N. K. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Hazry, D. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Khairunizam, Wan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Shahriman, A. B. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Yaacob, S. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; and others
2014-12-04
This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.
Bukhsh, Waqquas Ahmed
2014-07-01
Optimization plays a central role in the control and operation of electricity power networks. In this thesis we focus on two very important optimization problems in power systems. The first is the optimal power flow ...
Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report
Detwiler, Russell
2014-04-30
Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-?2013) and partially supported a post-?doctoral scholar (Dr. Jean Elkhoury; 2010-?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-?water or water-?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-? resolution mechanistic model that couples elastic deformation of contacts and aperture-?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.
Hagen, Stephen J.
Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J i.d.) at a speed 20 cm/s, under laminar flow conditions (Re 14). Construction from a fused silica studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial
Guidoboni, Giovanna
2007-01-01
J. Non-Newtonian Fluid Mech. 142 (2007) 36Â62 Review On the numerical simulation of Bingham visco-plastic various results and methods concerning the numerical simulation of Bingham visco-plastic flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2. On the modeling of Bingham viscous plastic flow
Direct numerical simulations of fluid flow, heat transfer and phase changes
Juric, D.; Tryggvason, G.; Han, J.
1997-04-01
Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.
The Properties of Confined Water and Fluid Flow at the Nanoscale
Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G
2009-03-09
This project has been focused on the development of accurate computational tools to study fluids in confined, nanoscale geometries, and the application of these techniques to probe the structural and electronic properties of water confined between hydrophilic and hydrophobic substrates, including the presence of simple ions at the interfaces. In particular, we have used a series of ab-initio molecular dynamics simulations and quantum Monte Carlo calculations to build an understanding of how hydrogen bonding and solvation are modified at the nanoscale. The properties of confined water affect a wide range of scientific and technological problems - including protein folding, cell-membrane flow, materials properties in confined media and nanofluidic devices.
Cirpka, Olaf Arie
allows the coupling of a laminar single-phase free flow and a two-phase porous-medium flow under non be necessary Coupling Situation coupling exists for laminar free flow (Mostaf et al. 2011) boundary layer DuMux in use for Darcy flow and laminar Stokes flow no RANS solver in DuMux or DUNE PDELab Open
Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing
Freifeld, B.; Finsterle, S.
2010-12-10
The objective of Task 2 is to develop a numerical method for the efficient and accurate analysis of distributed thermal perturbation sensing (DTPS) data for (1) imaging flow profiles and (2) in situ determination of thermal conductivities and heat fluxes. Numerical forward and inverse modeling is employed to: (1) Examine heat and fluid flow processes near a geothermal well under heating and cooling conditions; (2) Demonstrate ability to interpret DTPS thermal profiles with acceptable estimation uncertainty using inverse modeling of synthetic temperature data; and (3) Develop template model and analysis procedure for the inversion of temperature data collected during a thermal perturbation test using fiber-optic distributed temperature sensors. This status report summarizes initial model developments and analyses.
Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein
Walsh, Michael M. (Fairfield, CT)
2000-01-01
A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).
Gupta, Shubham, Ph. D. Massachusetts Institute of Technology
2012-01-01
We propose a tractable optimization framework for network Air Traffic Flow Management (ATFM) with an eye towards the future. The thesis addresses two issues in ATFM research: a) fairness and collaboration amongst airlines; ...
de Stadler, M; Chand, K
2007-11-12
Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are presented.
Flows of Incompressible Newtonian and Generalized Newtonian Fluids over a Circular Cylinder
Klein, Kayla
2012-05-31
This thesis presents numerical solutions of the boundary value problems describing the isothermal and non-isothermal steady flows of incompressible Newtonian, power-law and Carreau fluids over a circular cylinder using the hpk-finite element process...g_i...max <= O(10^-6) always ensures that Newton's linear method with line search yields an accurate solution of the system of non-linear algebraic equations resulting from the least squares process. The residual functional values of the order of O (10^-6) or lower ensure that GDEs are satisfied accurately over the entire domain and, thus the numerical solutions presented in this thesis can be viewed as benchmark quality solutions. In cases of generalized Newtonian fluids (power-law and Carreau models) only shear thinning fluids are considered. Numerical studies demonstrate decoupled behavior of the temperature field from the rest of the deformation field. Shear thinning behavior and viscous dissipation for progressively increasing Reynolds numbers are simulated accurately without any difficulty....
Dynamical Instability of Laminar Axisymmetric Flow of Perfect Fluid with Stratification
V. V. Zhuravlev; N. I. Shakura
2007-09-12
The instability of non-homoentropic axisymmetric flow of perfect fluid with respect to non-axisymmetric infinitesimal perturbations was investigated by numerical integration of hydrodynamical differential equations in two-dimensional approximation. The non-trivial influence of entropy gradient on unstable sound and surface gravity waves was revealed. In particular, both decrease and growth of entropy against the direction of effective gravitational acceleration $g_{eff}$ give rise to growing surface gravity modes which are stable with the same parameters in the case of homoentropic flow. At the same time increment of sound modes either grows monotonically while the rate of entropy decrease against $g_{eff}$ gets higher or vanishes at some values of positive and negative entropy gradient in the basic flow. The calculations have showed also that growing internal gravity modes appear only in the flow unstable to axisymmetric perturbations. At last, the analysis of boundary problem with free boundaries uncovered that's incorrect to set the entropy distribution according to polytropic law with polytropic index different from adiabatic value, since in this case perturbations don't satisfy the free boundary conditions.
Tao, Y.B.; He, Y.L.
2010-10-15
A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)
1464 IEEE TRANSACTIONS ON SMART GRID, VOL. 4, NO. 3, SEPTEMBER 2013 Distributed Optimal Power Flow
Giannakis, Georgios
--Distributed optimization, distribution feeders, microgrids, optimal power flow, semidefinite relaxation. I. INTRODUCTION MICROGRIDS are portions of a power distribution net- work located downstream of the distribution substation) and energy storage devices [1]. A microgrid can operate in either grid-connected, islanded, or hybrid modes
GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS
Johansen, Tor Arne
1 GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS MSc. Hans, NTNU, Trondheim, Norway Abstract A mathematical program for finding the optimal oil production rates in an oil production system is developed. Each well may be manipulated by injecting lift gas and adjusting
Edinburgh Research Explorer Local solutions of the optimal power flow problem
Millar, Andrew J.
law (KVL), which describes the flow of power in transmission lines, and is a nonlinear function of bus is to find a steady state operating point that minimizes the cost of electric power generation whileEdinburgh Research Explorer Local solutions of the optimal power flow problem Citation
Distributed Multi-Period Optimal Power Flow for Demand Response in Microgrids
Yeoh, William
Distributed Multi-Period Optimal Power Flow for Demand Response in Microgrids Paul Scott1 direction method of multipliers (ADMM), can be adapted to remain practical in this challenging microgrid discrete decisions. Our experiments on a suburb-sized microgrid show that the AC power flows and a simple
in the fractured media results in changes in the pore pressure and consequently causes changes in the effective of fluids is accompanied by substantial change in the pore pressure field. As fluids drain, pore pressure velocities) and decreasing permeability (Schoenberg, 2002). Conversely, pore pressure buildup due
Multiparticle imaging technique for two-phase fluid flows using pulsed laser speckle velocimetry
Hassan, T.A.
1992-12-01
The practical use of Pulsed Laser Velocimetry (PLV) requires the use of fast, reliable computer-based methods for tracking numerous particles suspended in a fluid flow. Two methods for performing tracking are presented. One method tracks a particle through multiple sequential images (minimum of four required) by prediction and verification of particle displacement and direction. The other method, requiring only two sequential images uses a dynamic, binary, spatial, cross-correlation technique. The algorithms are tested on computer-generated synthetic data and experimental data which was obtained with traditional PLV methods. This allowed error analysis and testing of the algorithms on real engineering flows. A novel method is proposed which eliminates tedious, undersirable, manual, operator assistance in removing erroneous vectors. This method uses an iterative process involving an interpolated field produced from the most reliable vectors. Methods are developed to allow fast analysis and presentation of sets of PLV image data. Experimental investigation of a two-phase, horizontal, stratified, flow regime was performed to determine the interface drag force, and correspondingly, the drag coefficient. A horizontal, stratified flow test facility using water and air was constructed to allow interface shear measurements with PLV techniques. The experimentally obtained local drag measurements were compared with theoretical results given by conventional interfacial drag theory. Close agreement was shown when local conditions near the interface were similar to space-averaged conditions. However, theory based on macroscopic, space-averaged flow behavior was shown to give incorrect results if the local gas velocity near the interface as unstable, transient, and dissimilar from the average gas velocity through the test facility.
Spane, Frank A.
2013-04-29
Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects
Siddiqui, Abuzar A
2011-01-01
Analytic expressions for the speed, flux, microrotation, stress, and couple stress in a micropolar fluid exhibiting steady, symmetric and one-dimensional electro-osmotic flow in a uniform cylindrical microcapillary were derived under the constraint of the Debye-Hueckel approximation, which is applicable when the cross-sectional radius of the microcapillary exceeds the Debye length, provided that the zeta potential is sufficiently small in magnitude. As the aciculate particles in a micropolar fluid can rotate without translation, micropolarity influences fluid speed, fluid flux, and one of the two non-zero components of the stress tensor. The axial speed in a micropolar fluid intensifies as the radius increases. The stress tensor is confined to the region near the wall of the microcapillary but the couple stress tensor is uniform across the cross-section.
Lopez, Jose M; Avila, Marc
2015-01-01
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Model Order Reduction in Porous Media Flow Simulation and Optimization
Ghasemi, Mohammadreza
2015-05-06
Subsurface flow modeling and simulation is ubiquitous in many energy related processes, including oil and gas production. These models are usually large scale and simulating them can be very computationally demanding, particularly in work...
Flow control optimization in a jet engine serpentine inlet duct
Kumar, Abhinav
2009-05-15
Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis which went in tandem with experimental investigation...
Influence of asperities on fluid and thermal flow in a fracture: a coupled Lattice Boltzmann study
Neuville, Amélie; Toussaint, Renaud
2013-01-01
The characteristics of the hydro-thermal flow which occurs when a cold fluid is injected into a hot fractured bedrock depend on the morphology of the fracture. We consider a sharp triangular asperity, invariant in one direction, perturbing an otherwise flat fracture. We investigate its influence on the macroscopic hydraulic transmissivity and heat transfer efficiency, at fixed low Reynolds number. In this study, numerical simulations are done with a coupled lattice Boltzmann method that solves both the complete Navier-Stokes and advection-diffusion equations in three dimensions. The results are compared with those obtained under lubrication approximations which rely on many hypotheses and neglect the three-dimensional (3D) effects. The lubrication results are obtained by analytically solving the Stokes equation and a two-dimensional (integrated over the thickness) advection-diffusion equation. We use a lattice Boltzmann method with a double distribution (for mass and energy transport) on hypercubic and cubic ...
Feeny, Brian
was restricted to the region near the jet exit and it involved jet--to--free stream velocity ratios (R v~/u0ABSTRACT The subject flow was created by the discharge of jet fluid, from a circular orifice by the free stream velocity, U, extant above the thin boundary layer (o
The Dynamics of Fluid Flow and Associated Chemical Fluxes at Active Continental Margins
Solomon, Evan A
2007-01-01
mixture of fluids introduced during drilling and in situfluid and sediment Ba concentrations from Ocean Drillingof drilling indicators (IR imagery and pore fluid chemical
The Dynamics of fluid flow and associated chemical fluxes at active continental margins
Solomon, Evan Alan
2007-01-01
mixture of fluids introduced during drilling and in situfluid and sediment Ba concentrations from Ocean Drillingof drilling indicators (IR imagery and pore fluid chemical
Liu, Hui-Hai
2011-01-01
gradient because water flux, energy gradient, and K areis equal to the energy carried by the water flowing into thevolume minus the energy carried by the water flowing out of
Computer Vision in Fluid Mechanics
Aminfar, AmirHessam
2015-01-01
Laminar flows are usually unidirectional flows, which the fluidlaminar flows ? Streak line: Streak line is locus of fluid
Abu-Hassoun, Amer H.
2009-05-15
the Super-K Zone was investigated. It is known that these zones are connected to naturally occurring fractures. Fluid flow in naturally fractured reservoirs is a very difficult mechanism to understand. To accomplish this mission, the Super-K Zone...
One Time-step Finite Element Discretization of the Equation of Motion of Two-fluid Flows
Maury, Bertrand
obtained at each time step when dis- cretizing the lubricated transportation of heavy crude oil in a horizontal pipeline. In the petroleum industry, an efficient way for transporting heavy crude oil to the pipe wall and it surrounds the fluid with high viscosity (heavy oil). It is assumed that the flow
Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Formation Timothy R. Kline of the driving forces for developing micro/nanofluidics. Engineering fluid flows at this scale remains a "fuel" can be converted locally at a catalyst surface, possibly eliminating external pumps or power
Matzen, G.W.
1997-01-01
Three-dimensional creeping flow around single, axisymmetric protrusions is studied numerically using the boundary-integral technique. Emphasis is placed upon cylindrical protrusions on plane walls for various height-to-radius (h-to-a) aspect ratios, but cones and sections of spheres protruding from plane walls are also briefly examined. The presented items include shear-stress distributions, shear-stress contours, extents of the fluid-flow disturbance, total forces and torques on the cylinders, streamlines, and skin-friction lines. Also included is a discussion of flow topology around axisymmetric geometries. No flow reversal is observed for cylindrical protrusions with aspect ratios greater than 2.4 to 2.6. At higher aspect ratios, the fluid tends to be swept around cylindrical protrusions with little vertical motion. At lower aspect ratios, the strength of the recirculation increases, and the recirculation region becomes wider in the transverse direction and narrower in the flow direction. Also, the recirculation pattern begins to resemble the closed streamline patterns in two-dimensional flow over square ridges. However, unlike two-dimensional flow, closed streamline patterns are not observed. For arbitrary axisymmetric geometries, the extent of the fluid-flow disturbance can be estimated with the total force that is exerted on the protrusion. When the same force is exerted on protrusions with different aspect ratios, the protrusion with the higher aspect ratio tends to have a greater disturbance in the flow direction and a smaller disturbance in the transverse direction. The total force exerted on cylindrical protrusions with rounded corners is only slightly lower than the total force exerted on cylindrical protrusions with sharp corners.
Liu, Feng
-objective design optimization of a transonic compressor rotor blade row. The adjoint method requires about twice single-objective design optimizations. Firstly a set of blades with different gains of total pressure Computational Fluid Dynamics (CFD), many research papers on design optimization of com- pressor blades have been
BiogeographyBiogeography--Based OptimizationBased Optimization of Power Flowof Power Flow
Simon, Dan
and phase angle vectors: 60 unknowns #12;7 Power Flow ProblemPower Flow Problem Cost Function = Power / Voltage Mismatch (Ideally = 0) ( ) ( ) ( ){ }2 2 2 min i Q i V i i Gen i PQ i PV P Q V + + V, V, V = - = - - = + - = + - a b #12;12 Simulation GA and BBO Performance ( )cost cost individual, generation, trial= ind trial gen
Kumar, Rakesh
2015-01-01
This investigation deals with the analysis of stagnation point heat transfer and corresponding flow features of hydromagnetic viscous incompressible fluid over a vertical shrinking sheet. The considered sheet is assumed to be permeable and subject to addition of stagnation point to control the generated vorticity in the boundary layer. The sheet is placed on the right side of the fluid saturated porous medium which is having permeability of specified form. Nonlinear convection waves in the flow field are realized due to the envisaged nonlinear relation between density and temperature. The equations governing the nonlinear convection boundary layer flow are modeled and simplified using similarity transformations. The economized equations are solved for numerical solutions by employing the implicit finite difference scheme also known as Keller-box method. The influence of the associated parameters of the problem on velocity and temperature distributions, skin friction and rate of heat transfer are presented thr...
Kim, Jihoon; Um, Evan; Moridis, George
2014-12-01
We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostly filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow-geomechanical simulator and are transformed via a rock-physics model into electrical conductivity models. It is shown that anomalous conductivity distribution in the resulting models is closely related to injected water saturation, but not closely related to newly created unsaturated fractures. Our numerical modeling experiments demonstrate that the crosswell EM method can be highly sensitive to conductivity changes that directly indicate the migration pathways of the injected fluid. Accordingly, the EM method can serve as an effective monitoring tool for distribution of injected fluids (i.e., migration pathways) during hydraulic fracturing operations
The impact of uncertainty on shape optimization of idealized bypass graft models in unsteady flow
Marsden, Alison L.
in the upstream proximal angle. The impact of cost function choice on the optimal solution was explored construction of a graft over a blocked blood vessel. Depending on the location and the underlying disease of surgical geometry on flow fields and hence wall- shear stress WSS , oscillatory shear index OSI , wall
Distributed Multi-Period Optimal Power Flow for Demand Response in Microgrids
Trumpf, Jochen
Distributed Multi-Period Optimal Power Flow for Demand Response in Microgrids Paul Scott Methodologies]: Artificial Intelligence Keywords OPF; ADMM; demand response; distributed control; micro- grid-coupled behaviours. In this new regime demand response (DR) techniques will play a central role in providing
Geologic constraints to fluid flow in the Jurassic Arab D reservoir, eastern Saudi Arabia
Laing, J.E. (Saudi Aramco, Dhahran (Saudi Arabia))
1991-08-01
A giant oil field located in eastern Saudi Arabia has produced several billion barrels of 37{degree} API oil from fewer than 100 wells. The Upper Jurassic Arab Formation is the main producing unit, and is made up of a series of upward-shoaling carbonate and anhydrite members. Porous carbonates of the Arab D member make up the principle oil reservoir, and overlying Arab D anhydrite provides the seal. Principal reservoir facies are stromatoporoid-coral and skeletal grainstones. Reservoir drive is currently provided by flank water injection. Despite more than 30 years of flank water injection (1.5 billion bbl) into the northern area of the field, a thick oil column remains in the Arab D reservoir. Geological factors which affect fluid flow in this area are (1) a downdip facies change from permeable skeletal-stromatoporoid limestone to less permeable micritic limestone, (2) vertical permeability barriers resulting from shoaling-upward cycles, (3) a downdip tar mat, (4) dolomite along the flanks in the upper portion of the reservoir, (5) highly permeable intervals within the skeletal-stromatoporoid limestone, and (6) an updip, north to south facies change from predominantly stromatoporoid-coral grainstone to skeletal grainstone. These factors are considered in reservoir modeling, simulation studies, and planning locations for both water injection and producer wells.
High vacuum measurements and calibrations, molecular flow fluid transient effects
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Leishear, Robert A.; Gavalas, Nickolas A.
2015-04-29
High vacuum pressure measurements and calibrations below 1 × 10-8 Torr are problematic. Specifically, measurement accuracies change drastically for vacuum gauges when pressures are suddenly lowered in vacuum systems. How can gauges perform like this? A brief system description is first required to answer this question. Calibrations were performed using a vacuum calibration chamber with attached vacuum gauges. To control chamber pressures, vacuum pumps decreased the chamber pressure while nitrogen tanks increased the chamber pressure. By balancing these opposing pressures, equilibrium in the chamber was maintained at selected set point pressures to perform calibrations. When pressures were suddenly decreased duringmore »set point adjustments, a sudden rush of gas from the chamber also caused a surge of gas from the gauges to decrease the pressures in those gauges. Gauge pressures did not return to equilibrium as fast as chamber pressures due to the sparse distribution of gas molecules in the system. This disparity in the rate of pressure changes caused the pressures in different gauges to be different than expected. This discovery was experimentally proven to show that different gauge designs return to equilibrium at different rates, and that gauge accuracies vary for different gauge designs due to fluid transients in molecular flow.« less
Wierman, Adam
.g., photovoltaic panels, wind turbines, electric vehicles, electronic appliances, and fuel cells, are easier2892 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 29, NO. 6, NOVEMBER 2014 Optimal Power Flow in Direct Current Networks Lingwen Gan and Steven H. Low, Fellow, IEEE Abstract--The optimal power flow (OPF
Stanley, H. Eugene
contribution to the laminar fluid flow through the void space. The calcu- lations we perform do not apply on Fluid Flow through Disordered Porous Media J. S. Andrade, Jr.,1,3 U. M. S. Costa,1 M. P. Almeida,1 H. A.11.+j A standard approach in the investigation of single- phase fluid flow in microscopically disordered
Lisburne Formation fracture characterization and flow modeling
Karpov, Alexandre Valerievich
2001-01-01
Evaluation of fractured reservoirs for fluid flow and optimal well placement is often very complicated. In general, fractures enhance permeability and increase access to matrix surface, but their random aspects create difficulties for analysis...
Kudrolli, Arshad
Onset of erosion of a granular bed in a channel driven by fluid flow Anyu Hong, Mingjiang Tao); 10.1063/1.4863989 Simulations of granular bed erosion due to laminar shear flow near the critical.1063/1.2213641 Onset of erosion and avalanche for an inclined granular bed sheared by a continuous laminar flow Phys
Opazo, A; Bustamante, G; Labbé, R
2015-01-01
We report experimental results for fluctuations of injected power in confined von K\\'arm\\'an swirling flows with constant external torque applied to the stirrers. Two experiments were performed at nearly equal Reynolds numbers in geometrically similar experimental setups, using air in one of them and water in the other. We found that the probability density function of power fluctuations is strongly asymmetric in air, while in water it is closer to a Gaussian, showing that the effect that a big change on the fluid density has on the flow-stirrer interaction is not reflected merely by a change in the amplitude of stirrers' response. In the case of water, with a density roughly 830 times greater than air density, the forcing exerted by the flow on the stirrers is stronger, so that they follow more closely the locally averaged rotation of the flow. When the fluid is air, the forcing is much weaker, resulting not only in a smaller stirrer response to the torque exerted by the flow, but also in power fluctuations ...
Williams, P.T.
1993-09-01
As the field of computational fluid dynamics (CFD) continues to mature, algorithms are required to exploit the most recent advances in approximation theory, numerical mathematics, computing architectures, and hardware. Meeting this requirement is particularly challenging in incompressible fluid mechanics, where primitive-variable CFD formulations that are robust, while also accurate and efficient in three dimensions, remain an elusive goal. This dissertation asserts that one key to accomplishing this goal is recognition of the dual role assumed by the pressure, i.e., a mechanism for instantaneously enforcing conservation of mass and a force in the mechanical balance law for conservation of momentum. Proving this assertion has motivated the development of a new, primitive-variable, incompressible, CFD algorithm called the Continuity Constraint Method (CCM). The theoretical basis for the CCM consists of a finite-element spatial semi-discretization of a Galerkin weak statement, equal-order interpolation for all state-variables, a 0-implicit time-integration scheme, and a quasi-Newton iterative procedure extended by a Taylor Weak Statement (TWS) formulation for dispersion error control. Original contributions to algorithmic theory include: (a) formulation of the unsteady evolution of the divergence error, (b) investigation of the role of non-smoothness in the discretized continuity-constraint function, (c) development of a uniformly H{sup 1} Galerkin weak statement for the Reynolds-averaged Navier-Stokes pressure Poisson equation, (d) derivation of physically and numerically well-posed boundary conditions, and (e) investigation of sparse data structures and iterative methods for solving the matrix algebra statements generated by the algorithm.
Plamin, Sammazo Jean-bertrand
2013-09-29
Two methods of hydraulic fracturing most widely utilized on unconventional shale gas and oil reservoirs are “gelled fracturing” and “slick-water fracturing”. Both methods utilize up to several million gallons of water-based fluid per well in a...
Qureshi, Maha
2013-09-29
Two methods of hydraulic fracturing most widely utilized on unconventional shale gas and oil reservoirs are “gelled fracturing” and “slick-water fracturing”. Both methods utilize up to several million gallons of water-based fluid per well in a...
for the Science of Light and Center for Medical Physics and Technology, Universitat Erlangen-Nurnberg, Erlangen-scale resolution. Using confocal microscopy, we directly image the drainage of the medium by the nonwetting oil and subsequent imbibition by the wetting fluid. During imbibition, the wetting fluid pinches off threads of oil
High Flash-point Fluid Flow System Aerosol Flammability Study and Combustion Mechanism Analysis
Huang, Szu-Ying
2013-12-02
regions of three main, widely-used commercial heat transfer fluids: Paratherm NF (P-NF); Dowtherm-600 (D-600); and Plate Heat Exchange Fluid (PHE), were analyzed by electro-spray generation with laser diffraction particle analysis method. The aerosol...
Rates of flow and patterns of fluid circulation Andrew T. Fisher
Fisher, Andrew
control the efficiency of lithospheric heat extraction, the nature of fluidrock interaction, and the extent of seafloor and sub-seafloor biospheres supported by fluid, energy, and solute fluxes. It has been both active and fossil systems, with the former often restricted to widely spaced or isolated boreholes
Swirling structure for mixing two concentric fluid flows at nozzle outlet
Mensink, Daniel L. (3578 Gregory La., Lynchburg, VA 24503)
1993-01-01
A nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.
Bowman, James Albert
1992-01-01
DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW-CUT IN SINGLE CRYSTAL QUARTZ A Thesis by JAlvlES ALBERT BOWMAN, JR, Submined to the Oflice of Graduate Studies of Texas A8r...M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Xiay I992 Major Subject: Geology DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW...
Rahatgaonkar, P. S.; Datta, D.; Malhotra, P. K.; Ghadge, S. G. [Nuclear Power Corporation of India Ltd., R-2, Ent. Block, Nabhikiya Urja Bhavan, Anushakti Nagar, Mumbai - 400 094 (India)
2012-07-01
Prediction of groundwater movement and contaminant transport in soil is an important problem in many branches of science and engineering. This includes groundwater hydrology, environmental engineering, soil science, agricultural engineering and also nuclear engineering. Specifically, in nuclear engineering it is applicable in the design of spent fuel storage pools and waste management sites in the nuclear power plants. Ground water modeling involves the simulation of flow and contaminant transport by groundwater flow. In the context of contaminated soil and groundwater system, numerical simulations are typically used to demonstrate compliance with regulatory standard. A one-dimensional Computational Fluid Dynamics code GFLOW had been developed based on the Finite Difference Method for simulating groundwater flow and contaminant transport through saturated and unsaturated soil. The code is validated with the analytical model and the benchmarking cases available in the literature. (authors)
CFD evaluation of pipeline gas stratification at low fluid flow due to temperature effects
Brar, Pardeep Singh
2005-02-17
It has been found through experiments at Southwest Research Institute that temperature differences between the gas and wall of the pipe through which the gas is flowing can greatly influence the gas flow in the pipe line ...
Fluid Flow and Thermodynamic Analysis of a Wing Anti-Icing System
is controlled through regulating the hot flow passing a wing anti-icing valve by an automatic control system
Stability and angular-momentum transport of fluid flows between corotating cylinders
Avila, Marc
2012-01-01
Turbulent transport of angular momentum is a necessary process to explain accretion in astrophysical disks. Although the hydrodynamic stability of disk-like flows has been tested in experiments, results are contradictory and suggest either laminar or turbulent flow. Direct numerical simulations reported here show that currently investigated laboratory flows are hydrodynamically unstable and become turbulent at low Reynolds numbers. The underlying instabilities stem from the axial boundary conditions, affect the flow globally and enhance angular-momentum transport.
Space-Time Discontinuous Galerkin Finite Element Method for Two-Fluid Flows.
Al Hanbali, Ahmad
flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed columns, fluidized beds, granular flows and ink spraying. The flow patterns in these problems are complex evolution, Rayleigh-Taylor and Kelvin-Helmholtz instabil- ities and industrial processes such as bubble
Flow through porous media : from mixing of fluids to triggering of earthquakes
Jha, Birendra, Ph. D. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
2014-01-01
Enhanced oil recovery by displacing oil with solvents such as carbon dioxide requires development of miscibility between the two fluids to maximize the displacement efficiency. Prevention of inadvertent triggering of ...
Interfacial exchange relations for two-fluid vapor-liquid flow : a simplified regime map approach
Kelly, J. E.
1981-01-01
A simplified approach is described for selection of the constitutive relations for the inter-phase exchange terms in the two-fluid code, THERMIT. The approach used distinguishes between pre-CHF and post-CHF conditions. ...
Pulsatile flow of a chemically-reacting non-linear fluid
Bridges, Ronald Craig, II
2007-09-17
Many complex biological systems, such as blood and polymeric materials, can be approximated as single constituent homogeneous fluids whose properties can change because of the chemical reactions that take place. For instance, ...
Lopez Hernandez, Henry De Jesus
2004-11-15
This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, ...
IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 15, NO. 2, MAY 2000 535 Stability-Constrained Optimal Power Flow Deqiang Gan, Member, IEEE, Robert J. Thomas, Fellow, IEEE, and Ray D. Zimmerman, Member, IEEE
McGrail, B.P.; Trent, D.S.; Terrones, G.; Hudson, J.D.; Michener, T.E.
1993-10-01
Safety of single-shell tanks containing ferrocyanide wastes is of concern. Ferrocyanide in the presence of an oxidizer such as NaNO{sub 3} or NaNO{sub 2} is explosively combustible when concentrated and heated. Evaluating the processes that could affect the fuel content of waste and distribution of the tank heat load is important. Highly alkaline liquid wastes were transferred in and out of the tanks over several years. Since Na{sub 2}NiFe(CN){sub 6} is much more soluble in alkaline media, the ferrocyanide could be dispersed from the tank more easily. If Cs{sub 2}NiFe(CN){sub 6} or CsNaNiFe(CN){sub 6} are also soluble in alkaline media, solubilization and transport of {sup 137}Cs could also occur. Transporting this heat generating radionuclide to a localized area in the tanks is a potential mechanism for generating a ``hot spot.`` Fluid convection could potentially speed the transport process considerably over aqueous diffusion alone. A stability analysis was performed for a dense fluid layer overlying a porous medium saturated by a less dense fluid with the finding that the configuration is unconditionally unstable and independent of the properties of the porous medium or the magnitude of the fluid density difference. A parametric modeling study of the buoyancy-driven flow due to a thermal gradient was combusted to establish the relationship between the waste physical and thermal properties and natural convection heat transfer. The effects of diffusion and fluid convection on the redistribution of the {sup 137}Cs were evaluated with a 2-D coupled heat and mass transport model. The maximum predicted temperature rise associated with the formation of zones was only 5{degrees}C and thus is of no concern in terms of generating a localized ``hot spot.``
Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)
1991-06-01
Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.
Use of Geophysical Techniques to Characterize Fluid Flow in a Geothermal Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Joint inversion of geophysical data for ground water flow imaging; Reduced the cost in geothermal exploration and monitoring; & Combined passive and active geophysical methods.
Numerical studies on two-way coupled fluid flow and geomechanics in hydrate deposits
Kim, J.
2014-01-01
A. 2008. Modeling of Geomechanics in Naturally Fracturedcoupling porous flow and geomechanics. Soc. Pet. Eng. J. 11(a reservoir simulator and a geomechanics module. Soc. Pet.
Marques, Alexandre Noll
2012-01-01
Numerical simulations of incompressible viscous flows in realistic configurations are increasingly important in many scientific and engineering fields. In Aeronautics, for instance, relatively cheap numerical computations ...
A Numerical Algorithm for Single Phase Fluid Flow in Elastic Porous ...
2000-11-13
flow in deforming saturated oil reservoirs, Int. J. Num. & Analy. Methods ... tion, New Mexico Institute of Mining and Technology, Socorro, NM,. 1998. [15] Raviart
Grothey, Andreas
is primarily due to Kirchhoff's voltage law (KVL), which describes the flow of power in transmission lines that minimizes the cost of electric power generation while satisfying operating constraints and meeting demandLocal Solutions of Optimal Power Flow Waqquas A. Bukhsh, Andreas Grothey, Ken McKinnon, and Paul
A Formal Model for Verifying the Impact of Stealthy Attacks on Optimal Power Flow in Power Grids
Wang, Yongge
- mal Power Flow; Formal Model 1. INTRODUCTION Power system control centers employ a numberA Formal Model for Verifying the Impact of Stealthy Attacks on Optimal Power Flow in Power Grids the integrity of OPF and undermine the economic and secure system operation. We present a formal verification
Bahrami, Majid
rise due to gravity. Assuming laminar flow and noting that 'z L, the pipe length, we get f 4 4 3 128 LQ is 30 cm higher than the surface of tank 2. (a) Estimate the flow rate in m3/h. Is the flow laminar? (b448 Solutions Manual x Fluid Mechanics, Fifth Edition f 1 2Thus h z z 0 by definition. Therefore
Airfoil Shape Optimization for Transonic Flows of BetheZel'dovichThompson Fluids
Paris-Sud XI, Université de
, in organic Rankine cycles (ORCs). Specific interest has developed in a particular class of dense gases, known in the same way as classical steam Rankine cycles, but due to the use of low-boiling compounds as working
PolitÃ¨cnica de Catalunya, Universitat
Engenharia Meca^nica, PontifiÂ´cia Universidade CatoÂ´lica do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro
Alan Black; Arnis Judzis
2005-09-30
This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2004 through September 2005. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all Phase 1 testing and is planning Phase 2 development.
Advanced Fluid Dynamics 2014 Sheet 5 Stokes flow around spherical particles
Hogg, Andrew
with no body force, where µ denotes the dynamic viscosity. Show that the stress tensor is given by ij = -2µ Ak xk ij + 2µ 2 xixj + xk 2 Ak xixj . (2) (b) Now consider the flow past a stationary sphere of radius the drag on the particle. 2. (a) Axisymmetric flow may be expressed in terms of spherical polar coordinates
Paden, Brad
Elimination of Adverse Leakage Flow in a Miniature Pediatric Centrifugal Blood Pump levitated centrifugal blood pump intended to deliver 0.31.5 l/min of support to neo- nates and infants by centrifugal force to flow radially outwards toward the outlet of the impeller against an unfavorable pressure
Rutqvist, J.
2010-06-01
This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC{sup 3D} geomechanical simulator. The most significant new TOUGH-FLAC development in the past few years is a revised architecture, enabling a more rigorous and tight coupling procedure with improved computational efficiency. The applications presented in this paper are related to modeling of crustal deformations caused by deep underground fluid movements and pressure changes as a result of both industrial activities (the In Salah CO{sub 2} Storage Project and the Geysers Geothermal Field) and natural events (the 1960s Matsushiro Earthquake Swarm). Finally, the paper provides some perspectives on the future of TOUGH-FLAC in light of its applicability to practical problems and the need for high-performance computing capabilities for field-scale problems, such as industrial-scale CO{sub 2} storage and enhanced geothermal systems. It is concluded that despite some limitations to fully adapting a commercial code such as FLAC{sup 3D} for some specialized research and computational needs, TOUGH-FLAC is likely to remain a pragmatic simulation approach, with an increasing number of users in both academia and industry.
Beresnev, Igor
of oil reservoirs 2 . For example, it is known that natural pressure in an oil reservoir generally yields naturally low mobility, and the enhanced oil recovery operations are used to increase pro- duction of a Maxwell fluid in a tube, which oscillates longitudinally and is subject to an oscillatory pressure
Application of a two-fluid model to simulate the heating of two-phase flows.
Saleh, Khaled
using an analytical solution. Eventually, a test case of the heating of a mixture of steam and water is presented, which is representative of a steam generator device. 1 Introduction Most of the industrial either as a coolant fluid or to ensure the production of mechanical work through the turbines which
Numerical simulation of flow of shear-thinning fluids in corrugated channels
Aiyalur Shankaran, Rohit
2009-05-15
industry. Since we are dealing with non-Newtonian fluids the non-linear terms in the constitutive equation have a significant affect on their behavior. The plates modeled for the study had a sinusoidal profile. A total of four different plates were...
Online Optimal Control of Connected Vehicles for Efficient Traffic Flow at Merging Roads
Rios-Torres, Jackeline [ORNL; Malikopoulos, Andreas [ORNL; Pisu, Pierluigi [Clemson University
2015-01-01
This paper addresses the problem of coordinating online connected vehicles at merging roads to achieve a smooth traffic flow without stop-and-go driving. We present a framework and a closed-form solution that optimize the acceleration profile of each vehicle in terms of fuel economy while avoiding collision with other vehicles at the merging zone. The proposed solution is validated through simulation and it is shown that coordination of connected vehicles can reduce significantly fuel consumption and travel time at merging roads.
Optimization of a high-efficiency jet ejector by computational fluid dynamic software
Watanawanavet, Somsak
2005-08-29
Research was performed to optimize high-efficiency jet ejector geometry (Holtzapple, 2001) by varying nozzle diameter ratios from 0.03 to 0.21, and motive velocities from Mach 0.39 to 1.97. The high-efficiency jet ejector was simulated by Fluent...
Cai, Xiao-Chuan
to blood flow modeling 6 Andrew T. Barker,a , Xiao-Chuan Caib a Department of Applied Mathematics@cs.colorado.edu (Xiao-Chuan Cai) Preprint submitted to Journal of Computational Physics September 24, 2009 #12
On the Fundamental Unsteady Fluid Dynamics of Shock-Induced Flows through Ducts
Mendoza, Nicole Renee
2013-04-29
Unsteady shock wave propagation through ducts has many applications, ranging from blast wave shelter design to advanced high-speed propulsion systems. The research objective of this study was improved fundamental understanding of the transient flow...
Multiphase fluid flow and time lapse seismics UNLP, 11 Octubre de
santos
The analysis of CO2 underground storage safety in the long term is a current area of research. ... the above PVT data. The Black-Oil equations for two-phase flow ...
A surfactant-conserving volume-of-fluid method for interfacial flows with insoluble surfactant
Lowengrub, John
of the interface. In the numerical method, the masses of the flow components and the surfactant mass are exactly.elsevier.com/locate/jcp #12;extraction and hydrodesulfurization of crude oil [3], polymer blending and plastic production [4
he behavior of fluid flows influences, and often determines, the performance of a large
Koochesfahani, Manoochehr M.
(IC) engines and combustors, aerodynamics of flow around objects moving in air and water, liquid into long-lifetime tracers when excited by photons of an appropriate wavelength. Typically a pulsed laser from a pulsed ex
, O. Le Metayer, A relaxation-projection method for compressible flows. Part II. The artificial heat speed causes inaccuracies in wave's transmission across interfaces. Moreover, volume fraction variation transmission of shocks across them. This formulation considerably simplifies numerical resolution. Following
Alfred, Dicman
2004-09-30
This research presents an approach to accurately simulate flow experiments through a fractured core using experimental, stochastic, and simulation techniques. Very often, a fracture is assumed as a set of smooth parallel plates separated by a...
Ground-penetrating radar imaging of fluid flow through a discrete fracture
Baker, Matthew Peter
2014-12-31
Predicting groundwater flow and transport of contaminants in fractured rock is challenging due to the heterogeneity of hydraulic properties that are difficult to characterize using conventional hydraulic testing methods. Heterogeneity is often...
Electromechanics and electrorheology of fluid flow with internal micro-particle electrorotation
Huang, Hsin-Fu
2010-01-01
The negative electrorheological responses of two dimensional Couette and Poiseuille flows with internal micro-particle electrorotation are modeled and analyzed via a set of "fully continuum mechanical modeling field ...
PROBABILISTIC SIMULATION OF SUBSURFACE FLUID FLOW: A STUDY USING A NUMERICAL SCHEME
Buscheck, Timothy Eric
1980-03-01
There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.
The role of homology in fluid vortices I: non-relativistic flow
D. H. Delphenich
2014-12-09
The methods of singular and de Rham homology and cohomology are reviewed to the extent that they are applicable to the structure and motion of vortices. In particular, they are first applied to the concept of integral invariants. After a brief review of the elements of fluid mechanics, when expressed in the language of exterior differential forms and homology theory, the basic laws of vortex theory are shown to be statements that are rooted in the homology theory of integral invariants.
Karra, Satish
2009-05-15
[35] developed a stability analysis for the ax- isymmetric Rayleigh instability as well as the non-axisymmetric whipping instability in Newtonian fluids. According to them, the Rayleigh instability due to electrical forces is equivalent to the surface... for viscoelasticity between the beads. . . . . . . . 19 7 Typical result for the discrete particle model showing the bending loop in the jet. Top view shows that the envelope of the jet trajectory is a cone. The number of beads for this simulation N = 100 and non...
Transient fluid and heat flow modeling in coupled wellbore/reservoir systems
Izgec, Bulent
2009-05-15
, asphaltene and timing of chemical injection, translating pressure-transient data when gathered above the perforations, production rate estimation by just using wellhead temperatures, and prediction of annular pressure buildup occurring in most subsea... for subsea completed wells. Pressure from fluid expansion is a natural occurrence in all wells. An explanation for the cause and effect of this type of pressure in addition to the cause and effect of pressure from external sources are examined. 8...
Hassan, T.A.
1992-12-01
The practical use of Pulsed Laser Velocimetry (PLV) requires the use of fast, reliable computer-based methods for tracking numerous particles suspended in a fluid flow. Two methods for performing tracking are presented. One method tracks a particle through multiple sequential images (minimum of four required) by prediction and verification of particle displacement and direction. The other method, requiring only two sequential images uses a dynamic, binary, spatial, cross-correlation technique. The algorithms are tested on computer-generated synthetic data and experimental data which was obtained with traditional PLV methods. This allowed error analysis and testing of the algorithms on real engineering flows. A novel method is proposed which eliminates tedious, undersirable, manual, operator assistance in removing erroneous vectors. This method uses an iterative process involving an interpolated field produced from the most reliable vectors. Methods are developed to allow fast analysis and presentation of sets of PLV image data. Experimental investigation of a two-phase, horizontal, stratified, flow regime was performed to determine the interface drag force, and correspondingly, the drag coefficient. A horizontal, stratified flow test facility using water and air was constructed to allow interface shear measurements with PLV techniques. The experimentally obtained local drag measurements were compared with theoretical results given by conventional interfacial drag theory. Close agreement was shown when local conditions near the interface were similar to space-averaged conditions. However, theory based on macroscopic, space-averaged flow behavior was shown to give incorrect results if the local gas velocity near the interface as unstable, transient, and dissimilar from the average gas velocity through the test facility.
Maiti, S; 10.1016/j.ijengsci.2011.05.006
2011-01-01
The paper deals with a theoretical study of the transport of a fluid in a channel, which takes place by the phenomenon of peristalsis. A mathematical analysis of the said problem has been presented. The analysis involves the application of a suitable perturbation technique. The velocity profile and the critical pressure for the occurrence of reflux are investigated with particular emphasis by using appropriate numerical methods. The effects of various parameters, such as Reynolds number, pressure gradient, porosity parameter, Darcy number, slip parameter, amplitude ratio and wave number on velocity and critical pressure for reflux are investigated in detail. The computed results are compared with a previous analytical work and an experimental investigation reported earlier in existing scientific literatures. The results of the present study are in conformity to both of them. The study has got some relevance to the physiological flow of bile in the common bile duct in a pathological state. It reveals that in t...
Kuntoro, Hadiyan Yusuf; Indarto,
2015-01-01
In the chemical, petroleum and nuclear industries, pipelines are often used to transport fluids from one process site to another one. The understanding of the fluids behavior inside the pipelines is the most important consideration for the engineers and scientists. From the previous studies, there are several two-phase flow patterns in horizontal pipe. One of them is stratified flow pattern, which is characterized by the liquid flowing along the bottom of the pipe and the gas moving above it cocurrently. Another flow patterns are slug and plug flow patterns. This kind of flow triggers the damage in pipelines, such as corrosion, abrasion, and blasting pipe. Therefore, slug and plug flow patterns are undesirable in pipelines, and the flow is maintained at the stratified flow condition for safety reason. In this paper, the analytical-based study on the experiment of the stratified flow pattern in a 26 mm i.d. horizontal pipe is presented. The experiment is performed to develop a high quality database of the stra...
Lopez, A.R.; Gritzo, L.A.; Hassan, B.
1997-06-01
For the purposes of designing improved Halon-alternative fire suppression strategies for aircraft applications, Computational Fluid Dynamics (CFD) simulations of the air flow, suppressant transport, and air-suppressant mixing within an uncluttered F18 engine nacelle were performed. The release of inert gases from a Solid Propellant Gas Generator (SPGG) was analyzed at two different injection locations in order to understand the effect of injection position on the flow patterns and the mixing of air and suppression agent. An uncluttered engine nacelle was simulated to provide insight into the global flow features as well as to promote comparisons with previous nacelle fire tests and recent water tunnel tests which included little or no clutter. Oxygen concentration levels, fuel/air residence times that would exist if a small fuel leak were present, velocity contours, and streamline patterns are presented inside the engine nacelle. The numerical results show the influence of the gent release location on regions of potential flame extinction due to oxygen inerting and high flame strain. The occurrence of inflow through the exhaust ducts on the aft end of the nacelle is also predicted. As expected, the predicted oxygen concentration levels were consistently higher than the measured levels since a fire was not modeled in this analysis. Despite differences in the conditions of these simulations and the experiments, good agreement was obtained between the CFD predictions and the experimental measurements.
Sundar, Sita; Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)
2012-05-15
In the interaction of intense lasers with matter/plasma, energetic electrons having relativistic energies get created. These energetic electrons can often have sheared flow profiles as they propagate through the plasma medium. In an earlier study [Phys. Plasmas 17, 022101 (2010)], it was shown that a relativistic sheared electron flow modifies the growth rate and threshold condition of the conventional Kelvin-Helmholtz instability. A perturbative analytic treatment for the case of weakly relativistic regime has been provided here. It provides good agreement with the numerical results obtained earlier.
Cubic law with aperture-length correlation: implications for network scale fluid flow
unit width normal to the direction of flow is proportional to the cubed aperture between the plates, fractures govern the hydraulic properties of these rocks (e.g. Bear et al. 1993; National Research Council; Brown 1987; Taylor et al. 1999; Rivard and Delay 2004). So far, however, both fields have mainly been
Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing
Office of Energy Efficiency and Renewable Energy (EERE)
Project objective: A New Geothermal Well Imaging Tool. 1.To develop a robust and easily deployable DTPS for monitoring in geothermal wells; and 2. Develop the associated analysis methodology for flow imaging; and?when possible by wellbore conditions?to determine in situthermal conductivity and basal heat flux.
Geodinamira Acta (Paris) 1998, 11, 2-3, 55-84 Compaction-driven fluid flow
Podladchikov, Yuri
scales. In viscous rock, inverted geothermal gradients stabilize vertically elon- gated waves or vertical geothermal gradients, thermally activated creep stabilizes hori- zontal waves, a geometry that was thought) the vertical length scale for compac- tion driven flow is generally constrained by the activation energy
Under consideration for publication in J. Fluid Mech. 1 Transcritical shallow-water flow past
wave amplitudes for the upstream and downstream undular bores, the speeds of the undular bores edges is with the upstream and downstream waves that may be generated for flow over a one-dimensional localized obstacle lee waves are found downstream, together with transients propagating both upstream and downstream
Olshanskii, Maxim A.
and accurate numerical methods for computing flows with free surfaces and interfaces, see, e.g., [1, 2 is studied in a series of numerical experiments. Institute of Numerical Mathematics, Russian Academy@math.uh.edu Department of Energy Resources Engineering, Stanford University and Institute of Numerical Mathematics
Mukhopadhyay, Sumit; Tsang, Yvonne W.
2008-08-01
Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper [Mukhopadhyay et al., 2008], we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks.
Christian Kreuzer; Endre Süli
2015-03-18
We develop the a posteriori error analysis of finite element approximations of implicit power-law-like models for viscous incompressible fluids. The Cauchy stress and the symmetric part of the velocity gradient in the class of models under consideration are related by a, possibly multi--valued, maximal monotone $r$-graph, with $\\frac{2d}{d+1}finite element residual, as well as the local stability of the error bound. We then consider an adaptive finite element approximation of the problem, and, under suitable assumptions, we show the weak convergence of the adaptive algorithm to a weak solution of the boundary-value problem. The argument is based on a variety of weak compactness techniques, including Chacon's biting lemma and a finite element counterpart of the Acerbi--Fusco Lipschitz truncation of Sobolev functions, introduced by L. Diening, C. Kreuzer and E. S\\"uli [Finite element approximation of steady flows of incompressible fluids with implicit power-law-like rheology. SIAM J. Numer. Anal., 51(2), 984--1015].
Proceedings: Joint DOE/NSF Workshop on flow of particulates and fluids
Not Available
1993-12-31
These proceedings are the result of the Fifth DOR-NSF Workshop on fundamental research in the area of particulate two-phase flow and granular flow. The present collection of twenty contributions from universities and national laboratories is based on research projects sponsored by either the Department of Energy or the National Science Foundation. These papers illustrate some of the latest advances in theory, simulations, and experiments. The papers from the Workshop held September 29--October 1, 1993 have been separated into three basic areas: experiments, theory, and numerical simulations. A list of attendees at the workshop is included at the end of the proceedings. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
The Center for Computational Sciences and Engineering (CCSE) develops and applies advanced computational methodologies to solve large-scale scientific and engineering problems arising in the Department of Energy (DOE) mission areas involving energy, environmental, and industrial technology. The primary focus is in the application of structured-grid finite difference methods on adaptive grid hierarchies for compressible, incompressible, and low Mach number flows. The diverse range of scientific applications that drive the research typically involve a large range of spatial and temporal scales (e.g. turbulent reacting flows) and require the use of extremely large computing hardware, such as the 153,000-core computer, Hopper, at NERSC. The CCSE approach to these problems centers on the development and application of advanced algorithms that exploit known separations in scale; for many of the application areas this results in algorithms are several orders of magnitude more efficient than traditional simulation approaches.
Triadic resonances in non-linear simulations of a fluid flow in a precessing cylinder
Giesecke, A; Gundrum, T; Herault, J; Stefani, F
2015-01-01
We present results from three-dimensional non-linear hydrodynamic simulations of a precession driven flow in cylindrical geometry. The simulations are motivated by a dynamo experiment currently under development at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in which the possibility of generating a magnetohydrodynamic dynamo will be investigated in a cylinder filled with liquid sodium and simultaneously rotating around two axes. In this study, we focus on the emergence of non-axisymmetric time-dependent flow structures in terms of inertial waves which - in cylindrical geometry - form so-called Kelvin modes. For a precession ratio ${\\rm{Po}}=\\Omega_p/\\Omega_c=0.014$ the amplitude of the forced Kelvin mode reaches up to one fourth of the rotation velocity of the cylindrical container confirming that precession provides a rather efficient flow driving mechanism even at moderate values of ${\\rm{Po}}$. More relevant for dynamo action might be free Kelvin modes with higher azimuthal wave number. These free Kelvin m...
Liu, Q. H. [University of Tennessee, Knoxville (UTK); Grim, G. M. [University of Tennessee, Knoxville (UTK); Papandrew, A [University of Tennessee, Knoxville (UTK); Turhan, A. [University of Tennessee, Knoxville (UTK); Zawodzinski, Thomas A [ORNL; Mench, Matthew M [ORNL
2012-01-01
The performance of a vanadium flow battery with no-gap architecture was significantly improved via several techniques. Specifically, gains arising from variation of the overall electrode thickness, membrane thickness, and electrode thermal treatment were studied. There is a trade-off between apparent kinetic losses, mass transfer losses, and ionic resistance as the electrode thickness is varied at the anode and cathode. Oxidative thermal pretreatment of the carbon paper electrode increased the peak power density by 16%. Results of the pretreatment in air showed greater improvement in peak power density compared to that obtained with pretreatment in an argon environment. The highest peak power density in a VRB yet published to the author s knowledge was achieved at a value of 767 mW cm 2 with optimized membrane and electrode engineering. 2012 The Electrochemical Society. [DOI: 10.1149/2.051208jes] All rights reserved.
Optimal operation of a concurrent-flow corn dryer with a drying heat pump using superheated steam
Moraitis, C.S. [Systelligence Consultants and Research Associates, Volos (Greece); Akritidis, C.B. [Dept. of Hydraulics and Agricultural Engineering, Thessaloniki (Greece)
1998-07-01
A numerical model of a concurrent-flow dryer of corn using superheated steam as drying medium is solved applying a shooting technique, so as to satisfy boundary conditions imposed by the optimal design of a drying heat pump. The drying heat pump is based on the theory of minimum energy cycles. The solution of the model proves the applicability of the heat pump to a concurrent-flow dryer, achieving a Specific Energy Consumption as low as 1080 kJ/kg.
Grujicic, Mica
2005-01-01
Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design A finite element method-based procedure is developed for the design of molecularly functionalized nano of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure
Edinburgh, University of
the overburden using vertical seismic profiles (VSPs) (Horne and MacBeth, 1997) and in the labora- Published for attenuation in the upper crust at seismic frequencies is intracrack fluid flow. In cracked media period of the workshop on Azimuthal Variations in Seismic Signature (held in conjunction with the 1997
Fakcharoenphol, Perapon; Xiong, Yi; Hu, Litang; Winterfeld, Philip H.; Xu, Tianfu; Wu, Yu-Shu
2013-05-01
TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.
Development of an entrained flow gasifier model for process optimization study
Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L. [Consorzio Pisa Ric, Pisa (Italy). Div Energia Ambiente
2009-10-15
Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.
Elliptic flow fluctuations in heavy ion collisions at RHIC and the perfect fluid hypothesis
Sascha Vogel; Giorgio Torrieri; Marcus Bleicher
2010-08-05
We analyse the recently measured $v_2$ fluctuation in the context of establishing the degree of fluidity of the matter produced in heavy ion collisions. We argue that flow observables within systems with a non-negligible mean free path should acquire a "dynamical" fluctuation, due to the random nature of each collision between the system's degrees of freedom. Because of this, $v_2$ fluctuations can be used to estimate the Knudsen number of the system produced at RHIC. To illustrate this quantitatively, we apply the UrQMD model, with scaled cross sections, to show that collisions at RHIC have a Knudsen number at least one order of magnitude above the expected value for an interacting hadron gas. Furthermore, we argue that the Knudsen number is also bound from above by the $v_2$ fluctuation data, because too large a Knudsen number would break the observed scaling of $v_2$ fluctuations due to the onset of turbulent flow. We propose, therefore that $v_2$ fluctuation measurements, together with an understanding of the turbulent regime for relativistic hydrodynamics, will provide an upper as well as a lower limit for the Knudsen number.
Wierman, Adam
Risk-Mitigated Optimal Power Flow for Wind Powered Grids Emma Sj¨odin, Dennice F. Gayme and Ufuk." High grid penetrations of solar or wind power pose a number of operational challenges and it is widely is the use of large-scale grid-integrated energy storage. The role of energy storage in power systems has
S Maiti; J. C. Misra
2011-07-28
The paper deals with a theoretical study of the transport of a fluid in a channel, which takes place by the phenomenon of peristalsis. A mathematical analysis of the said problem has been presented. The analysis involves the application of a suitable perturbation technique. The velocity profile and the critical pressure for the occurrence of reflux are investigated with particular emphasis by using appropriate numerical methods. The effects of various parameters, such as Reynolds number, pressure gradient, porosity parameter, Darcy number, slip parameter, amplitude ratio and wave number on velocity and critical pressure for reflux are investigated in detail. The computed results are compared with a previous analytical work and an experimental investigation reported earlier in existing scientific literatures. The results of the present study are in conformity to both of them. The study has got some relevance to the physiological flow of bile in the common bile duct in a pathological state. It reveals that in the presence of gallstones, bile velocity increases as the value of the porosity parameter increases, while the critical pressure for reflux decreases as porosity increases.
MECH 386 INDUSTRIAL FLUID MECHANICS INDUSTRIAL FLUID MECHANICS
Phani, A. Srikantha
technologies - Wind turbine - Wave energy (Wells turbine) - Tidal power 7. Flow in porous media - Darcy's law 8 fluid-mechanics research and its application, as well as the technology associated with fluid flow
Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization
Murray, Nathan E.
2012-03-12
Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a smaller aperture, 96-element array and a 200-meter tall meteorological tower. Analysis of the data successfully demonstrated the ability to estimate the vertical velocity profile using coherence data from the pressure array. Also, dynamical systems analysis methods were successful in identifying and tracking a gust type event. In addition to the passive acoustic profiling method, this program also investigated a rapid response Doppler SODAR system, the optimization of wind turbine blades for enhanced power with reduced aeroacoustic noise production, and the implementation of a wireless health monitoring system for the wind turbine blades. Each of these other objectives was met successfully. The use of phase unwrapping applied to SODAR data was found to yield reasonable results for per-pulse measurements. A health monitoring system design analysis was able to demonstrate the ability to use a very small number of sensors to monitor blade health based on the blade's overall structural modes. Most notable was the development of a multi-objective optimization methodology that successfully yielded an aerodynamic blade design that produces greater power output with reduced aerodynamic loading noise. This optimization method could be significant for future design work.
Xiong, Yi; Fakcharoenphol, Perapon; Wang, Shihao; Winterfeld, Philip H.; Zhang, Keni; Wu, Yu-Shu
2013-12-01
TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.
Self-Assembling Sup-porosity: The Effect On Fluid Flow And Seismic Wave Propagation
Pyrak-Nolte, Laura J.
2013-04-27
Fractures and joints in the field often contain debris within the void spaces. Debris originates from many different mechanisms: organic and/or inorganic chemical reactions/mineralization, sediment transport, formation of a fracture, mechanical weathering or combinations of these processes. In many cases, the presence of debris forms a â??sub-porosityâ? within the fracture void space. This sub-porosity often is composed of material that differs from the fracture walls in mineralogy and morphology. The â??sub-porosityâ? may partially fill voids that are on the order of hundreds of microns and thereby reduce the local porosity to lengths scales on the order of sub-microns to tens of microns. It is quite clear that a sub-porosity affects fracture porosity, permeability and storativity. What is not known is how the existence/formation of a sub-porosity affects seismic wave propagation and consequently our ability to probe changes in the subsurface caused by the formation or alteration of a sub-porosity. If seismic techniques are to be developed to monitor the injection and containment of phases in sequestration reservoirs or the propping of hydraulically induced fracture to enhance oil & gas production, it is important to understand how a sub-porosity within a fracture affects macroscopic seismic and hydraulic measurements. A sub-porosity will directly affect the interrelationship between the seismic and hydraulic properties of a fracture. This reports contains the results of the three main topics of research that were performed (1) to determine the effect of a sub-porosity composed of spherical grains on seismic wave propagation across fractures, (2) to determine the effect of biofilm growth in pores and between grains on seismic wave propagation in sediment, and (3) to determine the effect of the scale of observation (field-of-view) on monitoring alteration the pore space within a fracture caused by reactive flow. A brief summary of the results for each topic is contained in the report and the full details of the research and approach are contained in the publications found in the Attachment section of this report. A list of presentation and publications of all work associated with this grant is also provided.
A thermodynamic hypothesis regarding optimality principles for flow processes in geosystems
Liu, Hui-Hai
2015-01-01
basin has larger energy than the downstream water. Thus, thea way that the energy expenditure rate for water flow shouldhypothesis. The energy expenditure rate, EE, for water flow
Alan Black; Arnis Judzis
2003-10-01
This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2002 through September 2002. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit--fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. Accomplishments to date include the following: 4Q 2002--Project started; Industry Team was assembled; Kick-off meeting was held at DOE Morgantown; 1Q 2003--Engineering meeting was held at Hughes Christensen, The Woodlands Texas to prepare preliminary plans for development and testing and review equipment needs; Operators started sending information regarding their needs for deep drilling challenges and priorities for large-scale testing experimental matrix; Aramco joined the Industry Team as DEA 148 objectives paralleled the DOE project; 2Q 2003--Engineering and planning for high pressure drilling at TerraTek commenced; 3Q 2003--Continuation of engineering and design work for high pressure drilling at TerraTek; Baker Hughes INTEQ drilling Fluids and Hughes Christensen commence planning for Phase 1 testing--recommendations for bits and fluids.
Fluid-Particle and Fluid-Structure Interactions in Inertial Microfluidics
Amini, Hamed
2012-01-01
large-inertia laminar pipe flow. Journal of Fluid Mechanicsfluid are finite, still lies within the realm of laminar flow (
On-chip interconnection architecture optimization using a multicommodity flow approach
Hu, Yuanfang
2007-01-01
Routing Architecture Optimization . . . . . . . . . . . .Timing Analysis in On-Chip Interconnection ArchitectureLarge Scale On-Chip Interconnection Architecture Opti-
Stocker, H.
2012-01-01
Flow in Central High Energy Nuclear Collisions H. Stockera,under Contract High energy nuclear collisions offer a uniquesidewards flow·in high-energy nuclear collisions. The
Marinca, Vasile
2015-01-01
In this paper, Optimal Homotopy Perturbation Method (OHPM) is employed to determine an analytic approximate solutions for nonlinear MHD Jeffery-Hamel flow and heat transfer problem. The Navier-Stokes equations, taking into account Maxwell's electromagnetism and heat transfer lead to two nonlinear ordinary differential equations. The obtained results by means of OHPM show a very good agreement in comparison with the numerical results and with Homotopy Perturbation Method (HPM).
Boutchko, R.
2014-01-01
emission tomography systems and computational fluid dynamicsa computational ?uid dynamics (CFD) model of the systemthe computational domain. A Cartesian coordinate system was
Selective evaporation of focusing fluid in two-fluid hydrodynamic print head.
Keicher, David M.; Cook, Adam W.
2014-09-01
The work performed in this project has demonstrated the feasibility to use hydrodynamic focusing of two fluid steams to create a novel micro printing technology for electronics and other high performance applications. Initial efforts focused solely on selective evaporation of the sheath fluid from print stream provided insight in developing a unique print head geometry allowing excess sheath fluid to be separated from the print flow stream for recycling/reuse. Fluid flow models suggest that more than 81 percent of the sheath fluid can be removed without affecting the print stream. Further development and optimization is required to demonstrate this capability in operation. Print results using two-fluid hydrodynamic focusing yielded a 30 micrometers wide by 0.5 micrometers tall line that suggests that the cross-section of the printed feature from the print head was approximately 2 micrometers in diameter. Printing results also demonstrated that complete removal of the sheath fluid is not necessary for all material systems. The two-fluid printing technology could enable printing of insulated conductors and clad optical interconnects. Further development of this concept should be pursued.
Rutqvist, J.
2011-01-01
geomechanics and reservoir simulation. Society of Petroleumporous flow and geomechanics. Society of Petroleum Engineers
Fluid-cooled heat sink with improved fin areas and efficiencies for use in cooling various devices
Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth; Narumanchi, Sreekant
2015-04-21
The disclosure provides a fluid-cooled heat sink having a heat transfer base and a plurality of heat transfer fins in thermal communication with the heat transfer base, where the heat transfer base and the heat transfer fins form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop of the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.
Abbott, Mark W.
2013-07-01
Throughout power generation, delivery and waste remediation, the ability to control process streams in difficult or impossible locations becomes increasingly necessary as the complexity of processes increases. Example applications include radioactive environments, inside concrete installations, buried in dirt, or inside a shielded or insulated pipe. In these situations, it is necessary to implement innovative solutions to tackle such issues as valve maintenance, valve control from remote locations, equipment cleaning in hazardous environments, and flow stream analysis. The Extended Sleeve family of products provides a scalable solution to tackle some of the most challenging applications in hazardous environments which require flow stream control and monitoring. The Extended Sleeve family of products is defined in three groups: Extended Sleeve (ESV), Extended Bonnet (EBV) and Instrument Enclosure (IE). Each of the products provides a variation on the same requirements: to provide access to the internals of a valve, or to monitor the fluid passing through the pipeline through shielding around the process pipe. The shielding can be as simple as a grout filled pipe covering a process pipe or as complex as a concrete deck protecting a room in which the valves and pipes pass through at varying elevations. Extended Sleeves are available between roughly 30 inches and 18 feet of distance between the pipeline centerline and the top of the surface to which it mounts. The Extended Sleeve provides features such as ± 1.5 inches of adjustment between the pipeline and deck location, internal flush capabilities, automatic alignment of the internal components during assembly and integrated actuator mounting pads. The Extended Bonnet is a shorter fixed height version of the Extended Sleeve which has a removable deck flange to facilitate installation through walls, and is delivered fully assembled. The Instrument Enclosure utilizes many of the same components as an Extended Sleeve, yet allows the installation of process monitoring instruments, such as a turbidity meter to be placed in the flow stream. The basis of the design is a valve body, which, rather than having a directly mounted bonnet has lengths of concentric pipe added, which move the bonnet away from the valve body. The pipe is conceptually similar to an oil field well, with the various strings of casing, and tubing installed. Each concentric pipe provides a required function, such as the outermost pipes, the valve sleeve and penetration sleeve, which provide structural support to the deck flange. For plug valve based designs, the next inner pipe provides compression on the environmental seals at the top of the body to bonnet joint, followed by the innermost pipe which provides rotation of the plug, in the same manner as an extended stem. Ball valve ESVs have an additional pipe to provide compressive loading on the stem packing. Due to the availability of standard pipe grades and weights, the product can be configured to fit a wide array of valve sizes, and application lengths, with current designs as short as seven inches and as tall as 18 feet. Central to the design is the requirement for no special tools or downhole tools to remove parts or configure the product. Off the shelf wrenches, sockets or other hand tools are all that is required. Compared to other products historically available, this design offers a lightweight option, which, while not as rigidly stiff, can deflect compliantly under extreme seismic loading, rather than break. Application conditions vary widely, as the base product is 316 and 304 stainless steel, but utilizes 17-4PH, and other allows as needed based on the temperature range and mechanical requirements. Existing designs are installed in applications as hot as 1400 deg. F, at low pressure, and separately in highly radioactive environments. The selection of plug versus ball valve, metal versus soft seats, and the material of the seals and seats is all dependent on the application requirements. The design of the Extended Sleeve family of products provid
LaBonte, Alison L
2007-01-01
An Acoustically-Linked Moored Buoy Ocean ObservatoryAn Acoustically-Linked Moored-Buoy Ocean Observatory, Eosrecorded at Moss Landing NOAA buoy. A) flow rate (m/yr) flow
Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad
2006-06-06
A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.
Miller, Jan D; Hupka, Jan; Aranowski, Robert
2012-11-20
A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.
Bianco, Ronald
2013-12-02
have an increased localization toward the boundaries of the gouge layer (type III), and no occurrence of distributed (type I) shear. Systems with lower N and k show liquefaction events. Liquefaction events originate from increases in fluid pressure...
Kondle, Satyanarayana
2011-10-21
the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done...
Jain, Antone Kumar
2009-01-01
We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on ...
Corina Fetecau; C. Fetecau; A. Mahmood; E. Axinte
2009-09-16
Exact and approximate expressions are established for dissipation, the power of the shear stress at the wall and the boundary layer thickness corresponding to the motion of an Oldroyd-B fluid induced by a constantly accelerating plate. The similar expressions for Maxwell, Newtonian and second grade fluids, performing the same motion, are obtained as limiting cases of our general results. The specific features of the four models are emphasized by means of the asymptotic approximations.
Khan, Arshad; Khan, Ilyas; Shafie, Sharidan [Faculty of Science, Universiti Teknologi Malaysia (Malaysia)
2014-06-19
This article studies the radiation and porosity effects on the unsteady magnetohydrodynamic free convection flow of an incompressible viscous fluid past an infinite vertical plate that applies a shear stress f(t) to the fluid. Conjugate phenomenon of heat and mass transfer is considered. General solutions of the dimensionless governing equations along with imposed initial and boundary conditions are determined using Laplace transform technique. The solution of velocity is presented as a sum of mechanical and non mechanical parts. These solutions satisfy all imposed initial and boundary conditions and reduce to some known solutions from the literature as special cases. The results for embedded parameters are shown graphically. Numerical results for skin friction, Nusselt number and Sherwood number are computed and presented in tabular forms.
Lavaei, Javad
1 Abstract-- The optimal power flow (OPF) problem is a critical problem for power generation flow on the line P: vector of active power generations Q: vector of reactive power generations L: loss/reactive power generation limits. Given the practical importance of the problem, a great many studies have been
Boles, James R.; Garven, Grant
2015-08-04
Our studies have had an important impact on societal issues. Experimental and field observations show that CO_{2} degassing, such as might occur from stored CO_{2} reservoir gas, can result in significant stable isotopic disequilibrium. In the offshore South Ellwood field of the Santa Barbara channel, we show how oil production has reduced natural seep rates in the area, thereby reducing greenhouse gases. Permeability is calculated to be ~20-30 millidarcys for km-scale fault-focused fluid flow, using changes in natural gas seepage rates from well production, and poroelastic changes in formation pore-water pressure. In the Los Angeles (LA) basin, our characterization of formation water chemistry, including stable isotopic studies, allows the distinction between deep and shallow formations waters. Our multiphase computational-based modeling of petroleum migration demonstrates the important role of major faults on geological-scale fluid migration in the LA basin, and show how petroleum was dammed up against the Newport-Inglewood fault zone in a “geologically fast” interval of time (less than 0.5 million years). Furthermore, these fluid studies also will allow evaluation of potential cross-formational mixing of formation fluids. Lastly, our new study of helium isotopes in the LA basin shows a significant leakage of mantle helium along the Newport Inglewood fault zone (NIFZ), at flow rates up to 2 cm/yr. Crustal-scale fault permeability (~60 microdarcys) and advective versus conductive heat transport rates have been estimated using the observed helium isotopic data. The NIFZ is an important deep-seated fault that may crosscut a proposed basin decollement fault in this heavily populated area, and appears to allow seepage of helium from the mantle sources about 30 km beneath Los Angeles. The helium study has been widely cited in recent weeks by the news media, both in radio and on numerous web sites.
Optimizing flow rate and bacterial removal performance of ceramic pot filters in Tamale, Ghana
Zhang, Yiyue, S.M. Massachusetts Institute of Technology
2015-01-01
Pure Home Water (PHW) is an organization that seeks to improve the drinking water quality for those who do not have access to clean water in Northern Ghana. This study focuses on the further optimization of ceramic pot ...
Liu, G.; Liu, M.
2006-01-01
This paper presents a new building energy monitoring and pump speed control method. The pump speed is controlled to maintain the system resistance at an optimized value to approach the best pump efficiency and save pump power. The system resistance...
Shape optimized headers and methods of manufacture thereof
Perrin, Ian James
2013-11-05
Disclosed herein is a shape optimized header comprising a shell that is operative for collecting a fluid; wherein an internal diameter and/or a wall thickness of the shell vary with a change in pressure and/or a change in a fluid flow rate in the shell; and tubes; wherein the tubes are in communication with the shell and are operative to transfer fluid into the shell. Disclosed herein is a method comprising fixedly attaching tubes to a shell; wherein the shell is operative for collecting a fluid; wherein an internal diameter and/or a wall thickness of the shell vary with a change in pressure and/or a change in a fluid flow rate in the shell; and wherein the tubes are in communication with the shell and are operative to transfer fluid into the shell.
Bonne, U.; Vesovic, V.; Wakeham, W.A.
1996-07-15
The set published properties of gases constituting natural gas, at pressures up to 300 basr (4500 psi) ad for -40 less than or equal to T less than or equal to 250 deg C, is not accurate or consistent enough for members of hte gas industry, research groups, NGV-automotive engineers, and meter manufacturers to nondestructively calibrate existing, affordable, combustionless, on-line and in situ microsensors for their applications. Therefore, this study was set up to (1) establish a consistent set of thermophysical properties (thermal conductivity, viscosity, and isobaric heat capacity) of pure and mixed gas constituents of natural gases and (2) prove the validity and limitations of using one or more point sensors in suitable flow channels for the determination of total fluid flow.
A thermodynamic hypothesis regarding optimality principles for flow processes in geosystems
Liu, Hui-Hai
2015-01-01
structure of river basins. Water Resour Res 28:1095–1103of drainage networks. Water Resour Res 28:2183–2191 3. Liuhydraulic conductivity for water flow, in this case, is not
Optimization of Chilled Water Flow and Its Distribution in Central Cooling System
Maheshwari, G. P.; Hajiah, A. E.; ElSherbini, A. I.
2007-01-01
This paper analyzes the impact of chilled water flow and its distribution on energy efficiency and comfort quality, using the results of a field study conducted for a central cooling production system during 2006 in Kuwait. The paper identifies...
Li, Zhuoyi
2011-02-22
. Because of geothermal gradient, formation temperature along the depth of the wellbore changes significantly. At such a situation, some small thermal effects, such as fluid thermal expansion and viscous dissipation heating, can be ignored compared... data. For horizontal wells, because geothermal temperature changes are relatively small, the dominating effects on the wellbore temperature changes may be thermal expansion, viscous dissipative heating, and thermal conduction. Model for temperature...
Lecture notes Introductory fluid mechanics
Malham, Simon J.A.
Lecture notes Introductory fluid mechanics Simon J.A. Malham Simon J.A. Malham (15th September 2014 of fluid mechanics and along the way see lots of interesting applications. 2 Fluid flow, the Continuum are generally incompressible--a feature essential to all modern car braking mechanisms. Fluids can be further
Elmroth, Erik
of Energy's civilian nuclear waste management for the evaluation of the Yucca Mountain site as a repository groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal 6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid
Elmroth, Erik
with ¢¡¤£¦¥§ ¨¡© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning management for the evaluation of the Yucca Mountain site as a repository for nuclear wastes. In this context of developing a 3D flow model of the Yucca Mountain site, involving computational grids of to blocks
Approximating an Optimal Production Policy in a Continuous Flow Line: Recurrence and Asymptotic
Vázquez-Abad, Felisa J.
, production planning and schedul ing, producetostock, buffer size, buffer control, JIT systemsprone tandem machines. The production is regulated by a continuous version of buffer control. Our goal that for each feasible machine state, the optimal production control policy is to move the inventory levels
Improving electricity production in tubular microbial fuel cells through optimizing the anolyte h l i g h t s " The spiral spacers improve electricity production in tubular microbial fuel cells fuel cells Spiral spacers Energy Wastewater treatment a b s t r a c t The use of spiral spacers
Qin, Wensheng
. The use of methanol as solvent at the optimal conditions proved to be potential in making the system more. Introduction The world biodiesel production has been boosted in recent years owing to an increasing demand of renewable and sustainable energy. Glycerol is produced as a byproduct in the process of biodiesel production
Kimura, Nobuyuki; Hayashi, Kenji; Kamide, Hideki; Itoh, Masami; Sekine, Tadashi
2005-11-15
An innovative sodium-cooled fast reactor has been investigated in a feasibility study of fast breeder reactor cycle systems in Japan. A compact reactor vessel and a column-type upper inner structure with a radial slit for an arm of a fuel-handling machine (FHM) are adopted. Dipped plates are set in the reactor vessel below the free surface to prevent gas entrainment. We performed a one-tenth-scaled model water experiment for the upper plenum of the reactor vessel. Gas entrainment was not observed in the experiment under the same velocity condition as the reactor. Three vortex cavitations were observed near the hot-leg inlet. A vertical rib on the reactor vessel wall was set to restrict the rotating flow near the hot leg. The vortex cavitation between the reactor vessel wall and the hot leg was suppressed by the rib under the same cavitation factor condition as in the reactor. The cylindrical plug was installed through the hole in the dipped plates for the FHM to reduce the flow toward the free surface. It was effective when the plug was submerged into the middle height in the upper plenum. This combination of two components had a possibility to optimize the flow in the compact reactor vessel.
Finite element simulation of electrorheological fluids
Rhyou, Chanryeol, 1973-
2005-01-01
Electrorheological (ER) fluids change their flow properties dramatically when an electric field is applied. These fluids are usually composed of dispersions of polarizable particles in an insulating base fluid or composed ...
Multipurpose Acoustic Sensor for Downhole Fluid Monitoring
Broader source: Energy.gov [DOE]
Novel sensor design based on acoustics. Determine in real-timeand in a single sensor packagemultiple parameters: temperature, pressure, fluid flow; and fluid properties, such as density, viscosity, fluid composition.
Rutqvist, J.
2011-01-01
Analytical Methods in Geomechanics 17, 577–598. Liu, H.H. ,J.E. , 2003. Coupled geomechanics and reservoir simulation.coupling porous flow and geomechanics. Society of Petroleum
LaBonte, Alison Louise
2007-01-01
An Acoustically-Linked Moored Buoy Ocean ObservatoryAn Acoustically-Linked Moored-Buoy Ocean Observatory, Eosrecorded at Moss Landing NOAA buoy. A) CAT OTIS flow rate (
Priye, Aashish
2015-03-27
analysis app. These advancements make it possible to provide gold standard nucleic acid-based diagnostics to remote field sites using consumer class quad-copter drones. The surprising interplay between reactions and micro-scale convective flows led us...
Optimization Online Digest -- October 2015
Optimization Online Digest — October 2015. Applications — OR and Management Sciences Polynomial SDP Cuts for Optimal Power Flow Hassan Hijazi ...
Morozov, Victor (Manassas, VA)
2011-01-18
A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.
Liquid Metal Flow Can Be One Clue to Explain the Frequently Observed Fluid-Like Matters on Mars
Jing Liu; Yunxia Gao; Huangde Li
2013-10-07
The frequently discovered flooding structure on Mars and other planets has long been an intriguing mystery remained un-disclosed so far. Considering that on Earth, quite a few low melting point liquid metals or their alloy can be candidates of fluid like matters, we proposed here that there might also exists certain liquid metal instead of water or methane alone on Mars or the like planets. Compared with water, such liquid metal would be much easier to stay at the Mars surface because of its low melting point however extremely high evaporation point. Along this theoretical route, quite a few observations on the fluid like matters in former space explorations can be well interpreted. Such hypothesis for the existence of liquid metal on Mars surface does not mean refuting the possibility of water on Mars. This new point would be helpful for planning further exploration of Mars in a sense according to the characters of liquid metal. It at least identifies one more target fluid towards either finding or denying life at outer space. Whether the planet could harbor life in some form or it reaffirms Mars as an important future destination for human exploration still needs serious but not just enthusiasm explorations.
Ultrasonic fluid quality sensor system
Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)
2002-10-08
A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.
Ultrasonic Fluid Quality Sensor System
Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)
2003-10-21
A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.
Chance Constrained Optimal Power Flow: Risk-Aware Network Control under Uncertainty
Bienstock, Daniel; Harnett, Sean
2012-01-01
When uncontrollable resources fluctuate, Optimum Power Flow (OPF), routinely used by the electric power industry to re-dispatch hourly controllable generation (coal, gas and hydro plants) over control areas of transmission networks, can result in grid instability, and, potentially, cascading outages. This risk arises because OPF dispatch is computed without awareness of major uncertainty, in particular fluctuations in renewable output. As a result, grid operation under OPF with renewable variability can lead to frequent conditions where power line flow ratings are significantly exceeded. Such a condition, which is borne by simulations of real grids, would likely resulting in automatic line tripping to protect lines from thermal stress, a risky and undesirable outcome which compromises stability. Smart grid goals include a commitment to large penetration of highly fluctuating renewables, thus calling to reconsider current practices, in particular the use of standard OPF. Our Chance Constrained (CC) OPF correct...
Flow control techniques for real-time media applications in best-effort networks using fluid models
Konstantinou, Apostolos
2004-11-15
. : : : : : : : : : : : : : : : : : : : 84 35 Bu?er Level and Flow Rates for Reactive Controller 3 Simulation Using Cross-Tra?c 2. : : : : : : : : : : : : : : : : : : : : : : : : : : 85 36 End-to-End Delay, Source Bu?er Level and Losses for Reactive Controller 3 Simulation Using Cross.... : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 139 84 End-to-End Delay, Source Bu?er Level and Losses for Predictive Controller 2 Simulation Using Cross-Tra?c 1 for Application Send Rate of 180 ups and k2 = 0. : : : : : : : : : : : : : : : : : : : : : : : 140 85 Bu?er Level and Flow Rates...
Bush, John W.M.
, with the fluid sheet being the fish head and the tendrils its bones. Increasing the flow rate serves to broaden the fishbones. In the wake of the fluid fish, a regular array of drops obtains, the number and spacing of which
Solids mass flow determination
Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)
1981-01-01
Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.
Marcos, Ph.D. Massachusetts Institute of Technology
2011-01-01
Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...
A STOCHASTIC METHOD FOR MODELING FLUID DISPLACEMENT IN PETROLEUM RESERVOIRS
Anderson, C.
2011-01-01
FLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andFLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andachieve optimal recovery of petroleum from a reservoir, it
Multiphase fluid characterization system
Sinha, Dipen N.
2014-09-02
A measurement system and method for permitting multiple independent measurements of several physical parameters of multiphase fluids flowing through pipes are described. Multiple acoustic transducers are placed in acoustic communication with or attached to the outside surface of a section of existing spool (metal pipe), typically less than 3 feet in length, for noninvasive measurements. Sound speed, sound attenuation, fluid density, fluid flow, container wall resonance characteristics, and Doppler measurements for gas volume fraction may be measured simultaneously by the system. Temperature measurements are made using a temperature sensor for oil-cut correction.
Optimization of electrode characteristics for the Br2/H2 redox flow cell
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Nguyen, Trung V.
2014-10-01
The Br2/H2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (?) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (?) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm?2 and a peak power density of 1.4 W cm?2. Maximum energymore »efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br? reversibly adsorbs at the Pt (?) electrode for potentials exceeding a critical value, and the extent of Br? coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.« less
Optimization of electrode characteristics for the Br2/H2 redox flow cell
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Nguyen, Trung V.
2014-10-01
The Br2/H2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (?) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (?) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm?2 and a peak power density of 1.4 W cm?2. Maximum energy efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br? reversibly adsorbs at the Pt (?) electrode for potentials exceeding a critical value, and the extent of Br? coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.
Optimization of electrode characteristics for the Br?/H? redox flow cell
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Van Nguyen, Trung
2014-10-17
The Br?/H? redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (–) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (–) catalyst layer on the membrane instead of on the carbon-paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm-2 and a peak power density of 1.4 W cm-2. Maximum energy efficiencymore »of 79% is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br- reversibly adsorbs at the Pt (–) electrode for potentials exceeding a critical value, and the extent of Br- coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.« less
Optimization of electrode characteristics for the Br?/H? redox flow cell
Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Van Nguyen, Trung
2015-01-01
The Br?/H? redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (–) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (–) catalyst layer on the membrane instead of on the carbon-paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm^{-2 }and a peak power density of 1.4 W cm^{-2}. Maximum energy efficiency of 79% is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br^{-} reversibly adsorbs at the Pt (–) electrode for potentials exceeding a critical value, and the extent of Br^{-} coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.
Optimization of electrode characteristics for the Br-2/H-2 redox flow cell
Tucker, MC; Cho, KT; Weber, AZ; Lin, GY; Nguyen, TV
2014-10-17
The Br-2/H-2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (-) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (-) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm(-2) and a peak power density of 1.4 W cm(-2). Maximum energy efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br- reversibly adsorbs at the Pt (-) electrode for potentials exceeding a critical value, and the extent of Br- coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.
MacDonald, Mark
1 Title: Flow modeling in Pelton turbines by an accurate Eulerian and a fast Lagrangian evaluation Fluids Dynamics (CFD) has allowed the flow modeling in impulse hydro turbines that includes complex-parametric design optimization of the turbine's runner. In the present work, a CFD Eulerian approach is applied
Ultrasonic flow metering system
Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)
2002-01-01
A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.
Electrorheological fluids and methods
Green, Peter F.; McIntyre, Ernest C.
2015-06-02
Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.
Notes 09. Fluid inertia and turbulence in fluid film bearings
San Andres, Luis
2009-01-01
. Use the program to observe the effects of fluid inertia in the pressure field (shifting and increase/decrease) and the resulting forces. In addition, derive conclusions from the effects of the Gumbel cavitation condition on the fluid film forces.... Question to ponder: Does the physical modeling of liquid cavitation in superlaminar thin film flows must be revised? (Inertialess) Turbulent flow model for short length journal bearings Fluid inertia effects are not that important in a hydrodynamic...
Harmut Spetzler
2005-11-28
This paper describes the culmination of a research project in which we investigated the complex modulus change in partially fluid saturated porous rocks. The investigation started with simple flow experiments over ''clean'' and ''contaminated'' surfaces, progressed to moduli measurements on partially filled single cracks, to measurements in ''clean'' and ''contaminated'' porous rocks and finally to a feasibility study in the field. For the experiments with the simple geometries we were able to measure fundamental physical properties such as contact angles of the meniscus and time dependent forces required to get the meniscus moving and to keep it moving at various velocities. From the data thus gathered we were able to interpret the complex elastic moduli data we measured in the partially saturated single cracks. While the geometry in real rocks is too complex to make precise calculations we determined that we had indeed identified the mechanisms responsible for the changes in the moduli we had measured. Thus encouraged by the laboratory studies we embarked on a field experiment in the desert of Arizona. The field site allowed for controlled irrigation. Instrumentation for fluid sampling and water penetration were already in place. The porous loosely consolidated rocks at the site were not ideal for finding the effects of the attenuation mechanism we had identified in the lab, but for logistic and cost constraint reasons we chose to field test the idea at that site. Tiltmeters and seismometers were installed and operated nearly continuously for almost 3 years. The field was irrigated with water in the fall of 2003 and with water containing a biosurfactant in the fall of 2004. We have indications that the biosurfactant irrigation has had a notable effect on the tilt data.
Cho, KT; Albertus, P; Battaglia, V; Kojic, A; Srinivasan, V; Weber, AZ
2013-10-07
For storage of grid-scale electrical energy, redox-flow batteries (RFBs) are considered promising technologies. This paper explores the influence of electrolyte composition and ion transport on cell performance by using an integrated approach of experiments and cost modeling. In particular, the impact of the area-specific resistance on system capability is elucidated for the hydrogen/bromine RFB. The experimental data demonstrate very good performance with 1.46 W cm(-2) peak power and 4 A cm(-2) limiting current density at ambient conditions for an optimal cell design and reactant concentrations. The data and cost model results show that higher concentrations of RFB reactants do not necessarily result in lower capital cost as there is a tradeoff between cell performance and storage (tank) requirements. In addition, the discharge time and overall efficiency demonstrate nonlinear effects on system cost, with a 3 to 4 hour minimum discharge time showing a key transition to a plateau in terms of cost for typical RFB systems. The presented results are applicable to many different RFB chemistries and technologies and highlight the importance of ohmic effects and associated area-specific resistance on RFB viability.
Angel, S. Michael (Livermore, CA)
1989-01-01
Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.
Angel, S.M.
1987-02-27
Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.
Thanh D.B. Nguyen; Young-Il Lim; Seong-Joon Kim; Won-Hyeon Eom; Kyung-Seun Yoo [Hankyong National University, Jungangno (Republic of Korea). Laboratory of Functional Analysis of Complex Systems (FACS)
2008-11-15
A turbulent reacting flow computational fluid dynamics (CFD) model involving a droplet size distribution function in the discrete droplet phase is first built for selective noncatalytic reduction (SNCR) processes using urea solution as a NOx removal reagent. The model is validated with the experimental data obtained from a pilot-scale urea-based SNCR reactor installed with a 150 kW gas burner. New kinetic parameters of seven chemical reactions for the urea-based NOx reduction are identified and incorporated into the three-dimensional turbulent flow CFD model. The two-phase droplet model with the non-uniform droplet size is also combined with the CFD model to predict the trajectory of the droplets and to examine the mixing between the flue gas and reagents. The maximum NO reduction efficiency of about 80%, experimentally measured at the reactor outlet, is obtained at 940{degree}C and a normalized stoichiometric ratio (NSR) = 2.0 under the conditions of 11% excess air and low CO concentration (10-15 ppm). At the reaction temperature of 940{degree}C, the difference of a maximum of 10% between experiments and simulations of the NO reduction percentage is observed for NSR = 1.0, 1.5, and 2.0. The ammonia slip is overestimated in CFD simulation at low temperatures, especially lower than 900{degree}C. However, the CFD simulation results above 900{degree}C show a reasonable agreement with the experimental data of NOx reduction and ammonia slip as a function of the NSR. 31 refs., 3 figs., 6 tabs.
INTRODUCTION TO FLUID MECHANICS Spring 2011
Bahrami, Majid
Experiment 3: Basics of Fluid Mechanics, Friction in Laminar and Turbulent Pipe Flow Experiment:20, Wed 2:30 5:20, Fri 8:30 11:20, Lab 4302 Course Outline: Properties of fluids. Basic flow1 ENSC 283 INTRODUCTION TO FLUID MECHANICS Spring 2011 Instructor: Dr. Majid Bahrami 4372
Hartmann, Andreas; Clauser, Christoph
2008-01-01
Development of geothermal energy and basin-scale simulations of fluid and heat flow both suffer from uncertain physical rock properties at depth. Therefore, building better prognostic models are required. We analysed hydraulic and thermal properties of the major rock types in the Molasse Basin in Southern Germany. On about 400 samples thermal conductivity, density, porosity, and sonic velocity were measured. Here, we propose a three-step procedure with increasing complexity for analysis of the data set: First, univariate descriptive statistics provides a general understanding of the data structure, possibly still with large uncertainty. Examples show that the remaining uncertainty can be as high as 0.8 W/(m K) or as low as 0.1 W/(m K). This depends on the possibility to subdivide the geologic units into data sets that are also petrophysically similar. Then, based on all measurements, cross-plot and quick-look methods are used to gain more insight into petrophysical relationships and to refine the analysis. Be...
Lecture notes Introductory incompressible fluid mechanics
Malham, Simon J.A.
Lecture notes Introductory incompressible fluid mechanics Simon J.A. Malham Simon J.A. Malham (23rd of fluid mechanics and along the way see lots of interesting applications. 2 Fluid flow, the Continuum. Liquids are generally incompressible--a feature essential to all modern car braking mechanisms. Fluids can
Liu UCD Phy9B 07 1 Ch 14. Fluid Mechanics
Yoo, S. J. Ben
Flow Laminar flow: adjacent layers of fluid slide smoothly & flow steadily Turbulent flow: irregular & chaotic flow no steady-state pattern Continuity Equation Incompressible fluid: dm1=dm2 (A1v1dt= A2v2dt) A1v1= A2v2 Volume flow rate: dV/dt=Av Ideal fluid: incompressible ( const.) & no internal friction
Oborny, Michael C. (Albuquerque, NM); Paul, Phillip H. (Livermore, CA); Hencken, Kenneth R. (Pleasanton, CA); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)
2001-01-01
A valve for controlling fluid flows. This valve, which includes both an actuation device and a valve body provides: the ability to incorporate both the actuation device and valve into a unitary structure that can be placed onto a microchip, the ability to generate higher actuation pressures and thus control higher fluid pressures than conventional microvalves, and a device that draws only microwatts of power. An electrokinetic pump that converts electric potential to hydraulic force is used to operate, or actuate, the valve.
Fluid&ParticulateSystems 424514/2010
Zevenhoven, Ron
" Ron Zevenhoven ÅA Thermal and Flow Engineering ron.zevenhoven@abo.fi 9Fluid&ParticulateSystems 424514 Being often a low temperature process, better energy economy than, for example, distillation Fluid
Transient Temperature Modeling For Wellbore Fluid Under Static and Dynamic Conditions
Ali, Muhammad
2014-04-22
for geothermal wells and prediction of injection fluid temperatures. In this thesis, development and usage of three models for transient fluid temperature are presented. Two models predict transient temperature of flowing fluid under separate flow configurations...
Formulation of the Chip Cleanability Mechanics from fluid transport
Garg, Saurabh; Dornfeld, David; Berger, K.
2009-01-01
drag force. Fig. 10 A Laminar fluid flow profile through thefluid (water) under the experimental flow conditions used here, has an expected parabolic laminar
Formulation of the Chip Cleanability Mechanics from Fluid Transport
Garg, Saurabh; Dornfeld, David; Klaus Berger
2009-01-01
drag force. Fig. 10 A Laminar fluid flow profile through thefluid (water) under the experimental flow conditions used here, has an expected parabolic laminar
Journal of Fluid Mechanics http://journals.cambridge.org/FLM
Marusic, Ivan
the transition from smooth, laminar flow to turbulent flow and how the turbulence is then maintained. Recent of a spatially evolving boundary layer flow. These flows exist whenever there is fluid flow over a solid surfaceJournal of Fluid Mechanics http://journals.cambridge.org/FLM Additional services for Journal
Journal of Fluid Mechanics A furtive stare at an
Goldstein, Raymond E.
Journal of Fluid Mechanics Focus luids on F A furtive stare at an intra-cellular flow T. M. SQUIRES of the fluid flow within individual living cells, which agree quantitatively with their fluid mechanical model. Introduction Nature has long inspired researchers in fluid mechanics to explore the mechanical strategies used
Osinski, Charles Anthony
1963-01-01
the research. Assistance given the author by the staff of the Texas A. & M. Data Processing Center is also appreciated. I also wis'h to express my sincere appreciation to Colonel George E. Rath, USAF, without whose personal interest the opportunity... to the shearing rate, i. e. , or F/A & dv/dy dv dy or T (l) This is Newton's law of viscosity, where the constant of proportlonaltty, ~, is called the Newtonian viscosity. Newtonian viscosity is independent of shear under isothermal-isobaric conditions...
Sochi, Taha
2014-01-01
Several deterministic and stochastic multi-variable global optimization algorithms (Conjugate Gradient, Nelder-Mead, Quasi-Newton, and Global) are investigated in conjunction with energy minimization principle to resolve the pressure and volumetric flow rate fields in single ducts and networks of interconnected ducts. The algorithms are tested with seven types of fluid: Newtonian, power law, Bingham, Herschel-Bulkley, Ellis, Ree-Eyring and Casson. The results obtained from all those algorithms for all these types of fluid agree very well with the analytically derived solutions as obtained from the traditional methods which are based on the conservation principles and fluid constitutive relations. The results confirm and generalize the findings of our previous investigations that the energy minimization principle is at the heart of the flow dynamics systems. The investigation also enriches the methods of Computational Fluid Dynamics for solving the flow fields in tubes and networks for various types of Newtoni...
Alan Black; Arnis Judzis
2004-10-01
The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit-fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all major preparations for the high pressure drilling campaign. Baker Hughes encountered difficulties in providing additional pumping capacity before TerraTek's scheduled relocation to another facility, thus the program was delayed further to accommodate the full testing program.
Oil and Gas CDT Coupled flow of water and gas
Henderson, Gideon
, and experimental `toolbox' grounded in fluid mechanics and geomechanics, and specializing in multiphase flow
Zevenhoven, Ron
Introduction to Computational Fluid Dynamics 424512 E #1 - rz Introduction to Computational Fluid to Computational Fluid Dynamics 424512 E #1 - rz maj 2015 Åbo Akademi Univ - Thermal and Flow Engineering - Piispankatu 8, 20500 Turku 2 / 68 1.0 Course content / Time table #12;Introduction to Computational Fluid
Variational Methods for Computational Fluid Dynamics Annee 2013 -2014.
Alouges, François
are only valid for laminar flow at low Reynolds number. 4. Compute the flow rate F (the quantity of fluid that a fluid is flowing (from left to right) obeying Navier-Syokes equation. 1. Show that there is a stationary1 Variational Methods for Computational Fluid Dynamics Ann´ee 2013 - 2014. X2011. PC 1 Exercise 1
MEC E 230 Introduction to thermo-fluid sciences
Flynn, Morris R.
. Introduction to fluid mechanics. Fluid properties. Fluid statics. Use of control volumes. Internal flows. Pre in mechanical engineering. The physics of heat transfer and fluid mechanics are introduced. · Understand tension in calculating pressure in a fluid · Calculate static pressure and forces on immersed objects
Liles, D.R.
1982-01-01
Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced.
Wesfreid, José Eduardo
2013-01-01
, but of an assemblage of small-scale longitudinal vortices, separated from laminar flow by sharp fronts. For reviews undisturbed stable laminar Poiseuille flow up to Re = 5772 (Orszag 1971), but experiments show transition, surrounded by laminar ones. The inhomogeneity of flow friction generates a coupling between
Wesfreid, José Eduardo
1997-01-01
in a laminar boundary layer flow P. Petitjeans, J. E. Wesfreid, J. C. Attiach Abstract A new technique the effects of stretching on a controlled vorticity sheet coming from a laminar boundary layer flow on a flat. A diffuser keeps the flow laminar with a minimum of perturbation. The key elements of the channel
Semans, J.P.; Johnson, P.G.; LeBoeuf, R.F. Jr.; Kromka, J.A.; Goron, R.H.; Hay, G.D.
1991-04-30
This invention, a trainer mounted and housed within a mobile console, is used to teach and reinforce fluid principles to students. The system trainer has two centrifugal pumps, each driven by a corresponding two-speed electric motor. The motors are controlled by motor controllers for operating the pumps to circulate the fluid stored within a supply tank through a closed system. The pumps may be connected in series or in parallel. A number of valves are also included within the system to effect different flow paths for the fluid. In addition, temperature and pressure sensing instruments are installed throughout the closed system for measuring the characteristics of the fluid, as it passes through the different valves and pumps. These measurements are indicated on a front panel mounted to the console, as a teaching aid, to allow the students to observe the characteristics of the system.
Semans, Joseph P. (Uniontown, PA); Johnson, Peter G. (Pittsburgh, PA); LeBoeuf, Jr., Robert F. (Clairton, PA); Kromka, Joseph A. (Idaho Falls, ID); Goron, Ronald H. (Connellsville, PA); Hay, George D. (Venetia, PA)
1993-01-01
A trainer, mounted and housed within a mobile console, is used to teach and reinforce fluid principles to students. The system trainer has two centrifugal pumps, each driven by a corresponding two-speed electric motor. The motors are controlled by motor controllers for operating the pumps to circulate the fluid stored within a supply tank through a closed system. The pumps may be connected in series or in parallel. A number of valves are also included within the system to effect different flow paths for the fluid. In addition, temperature and pressure sensing instruments are installed throughout the closed system for measuring the characteristics of the fluid, as it passes through the different valves and pumps. These measurements are indicated on a front panel mounted to the console, as a teaching aid, to allow the students to observe the characteristics of the system.
Miller, Travis Reed
2010-01-01
This work aimed to inform the design of ceramic pot filters to be manufactured by the organization Pure Home Water (PHW) in Northern Ghana, and to model the flow through an innovative paraboloid-shaped ceramic pot filter. ...
Jordan Hristov
2011-07-26
Integral balance solution employing entire domain approximation and the penetration dept concept to the Stokes' first problem of a viscoelastic generalized second grade fluid has been developed. The solution has been performed by a parabolic profile with an unspecified exponent allowing optimization through minimization of the norm over the domain of the penetration depth. The closed form solution explicitly defines two dimensionless similarity variables and, responsible for the viscous and the elastic responses of the fluid to the step jump at the boundary. The solution was developed with three forms of the governing equation through its two dimensional forms (the main solution and example 1) and the dimensionless version showing various sides of the flow field and how the dimensionless groups control it: mainly the effect of the Deborah number. Numerical simulations demonstrating the effect of the various operating parameter and fluid properties on the developed flow filed have been performed.
GAS-PARTICLE FLOW IN THE ENTRY REGION OF A CURVED PIPE
Yeung, Woon-Shing
2011-01-01
=Equilibrium Fluid Dynamics-«Laminar Flow ?ver a Flat Plate.fluid is assumed to be incompressible and the flow nonseparating and laminar.
MECH 502: Fluid Mechanics Winter semester 2010
Phani, A. Srikantha
MECH 502: Fluid Mechanics Winter semester 2010 Instructor: I.A. Frigaard Times: Tuesdays week of semester. Location: CHBE 103 Synopsis: This course will focus primarily on fluid mechanics will be to look at fluid mechanics fundamentals, and at the mathematical modeling & analysis of simplified flow
Fluid Dynamics Research 40 (2008) 3444 A mixer design for the pigtail braid
Balasuriya, Sanjeeva
2008-01-01
, 2002) that even laminar fluid flows can stir a fluid effectively, provided that the Lagrangian particle baffles may be replaced by flow structures (such as periodic islands). © 2006 The Japan Society of Fluid Mechanics and Elsevier B.V. All rights reserved. Keywords: Chaotic advection; Braid; Stokes flow; Fluid
Greil, Oliver, E-mail: oliver.greil@roe.med.tu-muenchen.de; Kleinschmidt, Thomas; Weiss, Wolfgang [Technical University of Munich, Department of Interventional Radiology, Klinikum rechts der Isar (Germany); Wolf, Oliver; Heider, Peter [Technical University of Munich, Department of Vascular Surgery, Klinikum rechts der Isar (Germany); Schaffner, Silvio; Gianotti, Marc [Abbott Company, Vascular Devices (Switzerland); Schmid, Thomas; Liepsch, Dieter [University of Applied Science Munich, Laboratory for Fluid Mechanics (Germany); Berger, Hermann [Technical University of Munich, Department of Interventional Radiology, Klinikum rechts der Isar (Germany)
2005-01-15
Purpose. To study the influence of a newly developed membrane stent design on flow patterns in a physiologic carotid artery model. Methods. Three different stents were positioned in silicone models of the carotid artery: a stainless steel stent (Wall-stent), a nitinol stent (SelfX), and a nitinol stent with a semipermeable membrane (MembraX). To increase the contact area of the membrane with the vessel wall, another MembranX model was modified at the outflow tract. The membrane consists of a biocompatible silicone-polyurethane copolymer (Elast-Eon) with a pore size of 100 {mu}m. All stents were deployed across the bifurcation and the external carotid artery origin. Flow velocity measurements were performed with laser Doppler anemometry (LDA), using pulsatile flow conditions (Re = 220; flow 0.39 l/min; flow rate ratio ICA:ECA = 70:30) in hemodynamically relevant cross-sections. The hemodynamic changes were analyzed by comparing velocity fluctuations of corresponding flow profiles. Results. The flow rate ratio ICA:ECA shifted significantly from 70/30 to 73.9/26.1 in the MembraX and remained nearly unchanged in the SelfX and Wallstent. There were no changes in the flow patterns at the inflow proximal to the stents. In the stent no relevant changes were found in the SelfX. In the Wallstent the separation zone shifted from the orifice of the ICA to the distal end of the stent. Four millimeters distal to the SelfX and the Wallstent the flow profile returned to normal. In the MembraX an increase in the central slipstreams was found with creation of a flow separation distal to the stent. With a modification of the membrane this flow separation vanished. In the ECA flow disturbances were seen at the inner wall distal to the stent struts in the SelfX and the Wallstent. With the MembraX a calming of flow could be observed in the ECA with a slight loss of flow volume. Conclusions. Stent placement across the carotid artery bifurcation induces alterations of the physiologic flow behavior. Depending on the stent design the flow alterations are located in different regions. All the stents tested were suitable for the carotid bifurcation. The MembraX prototype has shown promising hemodynamic properties ex vivo.
Davis, Michael A.
2011-10-21
Single Duct Variable Air Volume (SDVAV) systems use series and parallel Fan Powered Terminal Units to control the air flow in conditioned spaces. This research developed a laboratory verified model of SDVAV systems that ...
Pfeiffer, Thomas
2011-02-22
algorithm h? photon energy GOC gas oil contact GOR gas oil ratio Ii incident light intensity It transmitted light intensity L half length of horizontal model LFA life fluid analyzer average chain length of mixture Ni chain length of component i... absorption tail. The Urbach phenomenology relates the electronic absorption coefficient ? exponentionally to the photon energy h?. (II.1) E0 is the Urbach decay width. The absorption coefficient is an intrinsic wavelength dependent property...
Optimization of Direct Ionization of CO2 by Controlling the Gas Flow Inside of a Beam-Target
Salazar Quintero, G A; Ognibene, T
2011-03-07
We designed and optimized a target that directs a CO{sub 2} pulse onto a Ti surface where a Cs{sup +} sputtering beam ionizes the CO{sub 2} to generate C{sup -}. These targets will be used for the direct ionization of CO{sub 2} pulses to enable the measurement of carbon isotope ratios in real time. The design was based on the results of Comsol{trademark} simulations of the target configurations.
arXiv:1301.0752v1[physics.flu-dyn]4Jan2013 Fluid-particle flow modelling and validation using
Luding, Stefan
-way-coupled mesoscale SPH-DEM Martin Robinsona, , Stefan Ludinga , Marco Ramaiolib aMultiscale Mechanics, University required to resolve the pore-scale is too great. It then becomes necessary to use unresolved, or mesoscale, fluid simulations. This mesoscale is the focus of this paper and the domain of applicability for the SPH
arXiv:1301.0752v1[physics.flu-dyn]4Jan2013 Fluid-particle flow modelling and validation using
Luding, Stefan
-way-coupled mesoscale SPH-DEM Martin Robinsona, , Stefan Ludinga , Marco Ramaiolib aMultiscale Mechanics, University to resolve the pore-scale is too great. It then becomes necessary to use unresolved, or mesoscale, fluid simulations. This mesoscale is the focus of this paper and the domain of applicability for the SPH-DEM method
Compressor bleed cooling fluid feed system
Donahoo, Eric E; Ross, Christopher W
2014-11-25
A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.
Optimizing Blast Furnace Operation to Increase Efficiency and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Optimizing Blast Furnace Operation to Increase Efficiency and Lower Costs State-of-the-Art Computational Fluid Dynamics Model Optimizes Fuel Rate in Blast Furnaces The blast...
Moridis, George; Freeman, Craig
2013-09-30
We developed two new EOS additions to the TOUGH+ family of codes, the RealGasH2O and RealGas . The RealGasH2O EOS option describes the non-isothermal two-phase flow of water and a real gas mixture in gas reservoirs, with a particular focus in ultra-tight (such as tight-sand and shale gas) reservoirs. The gas mixture is treated as either a single-pseudo-component having a fixed composition, or as a multicomponent system composed of up to 9 individual real gases. The RealGas option has the same general capabilities, but does not include water, thus describing a single-phase, dry-gas system. In addition to the standard capabilities of all members of the TOUGH+ family of codes (fully-implicit, compositional simulators using both structured and unstructured grids), the capabilities of the two codes include: coupled flow and thermal effects in porous and/or fractured media, real gas behavior, inertial (Klinkenberg) effects, full micro-flow treatment, Darcy and non-Darcy flow through the matrix and fractures of fractured media, single- and multi-component gas sorption onto the grains of the porous media following several isotherm options, discrete and fracture representation, complex matrix-fracture relationships, and porosity-permeability dependence on pressure changes. The two options allow the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in problems of geologic storage of greenhouse gas mixtures, and of geothermal reservoirs with multi-component condensable (H2O and CH4) and non-condensable gas mixtures. The codes are verified against available analytical and semi-analytical solutions. Their capabilities are demonstrated in a series of problems of increasing complexity, ranging from isothermal flow in simpler 1D and 2D conventional gas reservoirs, to non-isothermal gas flow in 3D fractured shale gas reservoirs involving 4 types of fractures, micro-flow, non-Darcy flow and gas composition changes during production.
Journal of Fluid Mechanics http://journals.cambridge.org/FLM
Marusic, Ivan
prove that the drag in pipe and channel flows of an unforced laminar fluid constitutes a lower bound drag reduction due to added polymers in Poiseuille flow. Journal of Fluid Mechanics, 659, pp 473483 to laminar fluids invariably increases drag. This proof does not rely on the adoption of a particular
Gray, Harold E. (Las Vegas, NV); McLaurin, Felder M. (Las Vegas, NV); Ortiz, Monico (Las Vegas, NV); Huth, William A. (Las Vegas, NV)
1996-01-01
A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.
Optimal Heat Transport in Rayleigh-B\\'enard Convection
Sondak, David; Waleffe, Fabian
2015-01-01
Steady flows that optimize heat transport are obtained for two-dimensional Rayleigh-B\\'enard convection with no-slip horizontal walls for a variety of Prandtl numbers $Pr$ and Rayleigh number up to $Ra\\sim 10^9$. Power law scalings of $Nu\\sim Ra^{\\gamma}$ are observed with $\\gamma\\approx 0.31$, where the Nusselt number $Nu$ is a non-dimensional measure of the vertical heat transport. Any dependence of the scaling exponent on $Pr$ is found to be extremely weak. On the other hand, the presence of two local maxima of $Nu$ with different horizontal wavenumbers at the same $Ra$ leads to the emergence of two different flow structures as candidates for optimizing the heat transport. For $Pr \\lesssim 7$, optimal transport is achieved at the smaller maximal wavenumber. In these fluids, the optimal structure is a plume of warm rising fluid which spawns left/right horizontal arms near the top of the channel, leading to downdrafts adjacent to the central updraft. For $Pr > 7$ at high-enough Ra, the optimal structure is a...
Microelectromechanical flow control apparatus
Okandan, Murat (NE Albuquerque, NM)
2009-06-02
A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.
Clement, Prabhakar
Pipe Flow System Design Holly Guest #12;Problem · An engineer is asked to compute the flow rate · Flow type: Turbulent or Laminar flow · Flow rate · Frictional head loss · Optimal diameters if a pump · = - ( . + . ) · f = friction factor · = relative roughness = · = Reynolds Number = · Laminar flow: 2000
Laser microfluidics : fluid actuation by light Laser microfluidics: fluid actuation by light
Paris-Sud XI, Université de
Laser microfluidics : fluid actuation by light Laser microfluidics: fluid actuation by light Jean.delville@cpmoh.u-bordeaux1.fr Abstract: The development of microfluidic devices is still hindered by the lack of robust to extend this concept to microfluidic two-phase flows. First, we investigate the destabilization of fluid
CE 576 Environmental Flows Spring 2012
Rehmann, Chris
.1. Conservation of mass 1.2. Conservation of momentum 2. Channel flows 2.1. Laminar flow 2.1.1. Flow in a tubeCE 576 Environmental Flows Spring 2012 Course information Instructor: Prof. Chris Rehmann rehmann in environmental fluid mechanics Prerequisites: Elementary fluid mechanics, calculus, differential equations
High-potential Working Fluids for Next Generation Binary Cycle Geothermal Power Plants
Broader source: Energy.gov [DOE]
DOE Geothermal Peer Review 2010 - Presentation. Project objective: Find optimized working fluid/advanced cycle combination for EGS applications.
Controller Synthesis for Periodic, Linear-Distributed Parameter Systems: Channel Flow Application
Kang, SM; Speyer, JL; Kim, J
2015-01-01
Flow,” Journal of Fluid Mechanics, Vol. 481, April 2003, pp.Streaks,” Journal of Fluid Mechanics, Vol. 537, Aug. 2005,Flow,” Journal of Fluid Mechanics, Vol. 558, July 2006, pp.
Mechanotransduction of fluid stresses governs 3D cell migration
Polacheck, William J.
Solid tumors are characterized by high interstitial fluid pressure, which drives fluid efflux from the tumor core. Tumor-associated interstitial flow (IF) at a rate of ?3 µm/s has been shown to induce cell migration in the ...
EFFICIENT NONPARAMETRIC DENSITY ESTIMATION ON THE SPHERE WITH APPLICATIONS IN FLUID MECHANICS
Egecioglu, Ömer
EFFICIENT NONPARAMETRIC DENSITY ESTIMATION ON THE SPHERE WITH APPLICATIONS IN FLUID MECHANICS ¨OMER density, nonparametric estimation, fluid mechanics, convergence, kernel method, efficient algorithm AMS, an important application of nonparametric density estimation is in computational fluid mechanics. When the flow
Fluid&ParticulateSystems 424514/2010
Zevenhoven, Ron
Potential energy Including flows of Kinetic energy Internal energy Flow energy Thermal energy Electrical - Steady state (no time derivates) - Thermal energy is omitted since temperature is assumed to remain Ron Zevenhoven ÅA Thermal and Flow Engineering ron.zevenhoven@abo.fi 1Fluid&ParticulateSystems 424514
Flores, Leona Marie
2010-01-01
laminar flow in a circular cylindrical tube, with the assumptions that blood is an incompressible Newtonian fluid, the flowLaminar Shear Flow Experiments A parallel-plate flow system was used to impose fluid
Optimization of Magnetic Refrigerators by Tuning the Heat Transfer Medium and Operating Conditions
Ghahremani, Mohammadreza; Bennett, Lawrence H; Della Torre, Edward
2015-01-01
A new experimental test bed has been designed, built, and tested to evaluate the effect of the systems parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a higher temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the systems optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in an AMR system. By optimizing these parameters the refrigeration performance increased by 24%. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.
Global Optimization of Optimal Power Flow
Grossmann, Ignacio E.
Multi-Period OPF `Smart Grid' · Transmission short falls due to Fluctuating demands. Integrating/03/2013 2 AC-OPF definition · Given: Topology of the power grid: generators, loads, power lines. · Objective: Find operating points for generators, (PG,QG) Minimizing cost of generation f(PG) · Satisfy
Spiral Laminar Flow: A revolution in understanding?
Greenaway, Alan
Blood Flow Spiral laminar flow #12;Spiral flow in the Aorta (MRI) Computational Fluid Dynamics 0 10 20Spiral Laminar Flow: A revolution in understanding? Reintroduction of natural blood flow Laminar Flow through Runoff (3months) Proximal Anastomosis SLF TM Graft Distal Anastomosis Post-op Angios
Pinkel, Daniel (Walnut Creek, CA)
1991-01-01
An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.
Pinkel, D.
1987-11-30
An obstruction across the flow chamber creates a one-dimensional convergence of a sheath fluid. A passageway in the obstruction directs flat cells near to the area of one-dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates. 6 figs.
Optimization of chemical etching process in niobium cavities
Tajima, T. (Tsuyoshi); Trabia, M.; Culbreth, W.; Subramanian, S.
2004-01-01
Superconducting niobium cavities are important components of linear accelerators. Buffered chemical polishing (BCP) on the inner surface of the cavity is a standard procedure to improve its performance. The quality of BCP, however, has not been optimized well in terms of the uniformity of surface smoothness. A finite element computational fluid dynamics (CFD) model was developed to simulate the chemical etching process inside the cavity. The analysis confirmed the observation of other researchers that the iris section of the cavity received more etching than the equator regions due to higher flow rate. The baffle, which directs flow towards the walls of the cavity, was redesigned using optimization techniques. The redesigned baffle significantly improves the performance of the etching process. To verify these results an experimental setup for flow visualization was created. The setup consists of a high speed, high resolution CCD camera. The camera is positioned by a computer-controlled traversing mechanism. A dye injecting arrangement is used for tracking the fluid path. Experimental results are in general agreement with CFD and optimization results.
Journal of Fluid Mechanics http://journals.cambridge.org/FLM
Marusic, Ivan
Terms of use : Click here Laminar and turbulent comparisons for channel flow and flow control IVAN and turbulent comparisons for channel flow and flow control. Journal of Fluid Mechanics, 570, pp 467477 doi:10 the discrepancy between the volume flux in laminar and in turbulent flow at the same pressure gradient increases
Elongational-flow-induced scission of DNA nanotubes in laminar flow Rizal F. Hariadi*
Winfree, Erik
-induced scission are pro- foundly affected by the fluid flow and the polymer bond strengths. In this paper, laminarElongational-flow-induced scission of DNA nanotubes in laminar flow Rizal F. Hariadi* Department libraries in shotgun ge- nome sequencing 24 . The fluid-flow-induced mechanical shearing of prion fibrils
Celik, I.; Chattree, M.
1988-07-01
An assessment of the theoretical and numerical aspects of the computer code, PCGC-2, is made; and the results of the application of this code to the Morgantown Energy Technology Center (METC) advanced gasification facility entrained-flow reactor, ''the gasifier,'' are presented. PCGC-2 is a code suitable for simulating pulverized coal combustion or gasification under axisymmetric (two-dimensional) flow conditions. The governing equations for the gas and particulate phase have been reviewed. The numerical procedure and the related programming difficulties have been elucidated. A single-particle model similar to the one used in PCGC-2 has been developed, programmed, and applied to some simple situations in order to gain insight to the physics of coal particle heat-up, devolatilization, and char oxidation processes. PCGC-2 was applied to the METC entrained-flow gasifier to study numerically the flash pyrolysis of coal, and gasification of coal with steam or carbon dioxide. The results from the simulations are compared with measurements. The gas and particle residence times, particle temperature, and mass component history were also calculated and the results were analyzed. The results provide useful information for understanding the fundamentals of coal gasification and for assessment of experimental results performed using the reactor considered. 69 refs., 35 figs., 23 tabs.